Supplementary uplink in wireless systems

ABSTRACT

Supplementary uplink (SUL) may be used in wireless systems. Cell suitability criteria may be provided for cells configured with SUL. A Wireless Transmit/Receive Unit (WTRU) may receive paging with an indication of a carrier (e.g., SUL or regular uplink (RUL)) in which to initiate part or all of an initial access. A WTRU that may be performing response-driven paging may provide (e.g. explicit) beam information for beamforming of a paging message on a non-beamformed SUL. A handover (HO) procedure (e.g., carrier selection, configuration handling, HO failure, etc.) may be provided for a WTRU with a configured SUL. A WTRU may request a change of a configured UL. A WTRU may (e.g., autonomously) perform a switch to a different (e.g., configured) uplink, for example, when one or more conditions may be met (e.g., conditional switch). Semi-persistent scheduling (SPS) resources/configuration may be relocated from a first UL to a second UL.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of Non-Provisional U.S. patentapplication Ser. No. 16/764,155, filed May 14, 2020, which is the U.S.National Stage, under 35 U.S.C. § 371, of International Application No.PCT/US2018/060947, filed Nov. 14, 2018, which claims the benefit ofProvisional U.S. Patent Application No. 62/629,901, filed Feb. 13, 2018,62/615,255, filed Jan. 9, 2018, and 62/585,878, filed Nov. 14, 2017, thedisclosures of which are incorporated herein by reference in theirentirety.

BACKGROUND

Mobile communications using wireless communication continue to evolve. Afifth generation may be referred to as 5G. A previous (legacy)generation of mobile communication may be, for example, fourthgeneration (4G) long term evolution (LTE).

SUMMARY

Systems, methods, and instrumentalities are disclosed for supplementaryuplink (SUL) in wireless systems. Cell suitability criteria may beprovided for cells configured with SUL. A WTRU may receive paging withan indication of a carrier (e.g. SUL or regular uplink (RUL)) in whichto initiate part or all of an initial access. A WirelessTransmit/Receive Unit (WTRU) that may be performing response-drivenpaging may provide (e.g. explicit) beam information for beamforming of apaging message on a non-beamformed SUL. A handover (HO) procedure (e.g.carrier selection, configuration handling, HO failure) may be providedfor a WTRU with a configured SUL. A WTRU may request a change of aconfigured UL. A WTRU may (e.g. autonomously) perform a switch to adifferent (e.g. configured) uplink, e.g., when one or more conditionsmay be met (e.g. conditional switch). Semi-persistent scheduling (SPS)resources/configuration may be relocated from a first UL to a second UL.Duplication and UL path selection may be provided for radio resourcecontrol (RRC) messages in the presence of an SUL. A WTRU may or may nottrigger radio link failure (RLF), for example, based on whether RLFrelated conditions occurred on SUL/RUL and based on SUL/RULconfiguration. Conditions may be set for suspension/reset of RLF relatedcounters/timers upon a switch between RUL/SUL. A WTRU may inform amaster node (MN) of an RUL/SUL configuration, for example, duringsecondary cell group (SCG) failure information reporting. A procedure(e.g. with corresponding WTRU behavior) may be implemented for partialSCG failure that may be triggered by SCG RLF on an RUL. A WTRU mayselect a UL carrier (e.g. SUL/RUL) on which to initiatere-establishment. Procedures may be provided for UL selection of asystem information (SI) request in the presence of an SUL/RUL.

A WTRU may receive a handover (HO) command, and select an uplink (UL)carrier for HO based on the HO command. For example, if the HO commandcomprises an explicit indication of one UL carrier for HO, then the WTRUmay select the UL carrier for HO based on whether random-access channel(RACH) resources are provided for a supplementary uplink (SUL) or aregular uplink (RUL) in the HO command. If the HO command comprises aconfiguration for both a SUL and a RUL in the HO command, then the WTRUmay select the UL carrier for HO based on whether a downlink referencesignal received power (DL-RSRP) of the SUL is below a threshold. Forexample, if the DL-RSRP of the SUL is below the threshold, then the SULis selected as the UL carrier for HO, and if the DL-RSRP of the SUL isequal to or above the threshold, then the RUL is selected as the ULcarrier for HO.

A wireless transmit/receive unit (WTRU), may use different cellsuitability criteria based on whether the cell is configured with a SULthat the WTRU supports. For example, the WTRU may determine suitabilityof a cell. If the cell is configured with a SUL and the WTRU supportsSUL communication for the frequency (e.g., SUL frequency) of the cell,then the WTRU may determine the suitability of the cell using first cellsuitability criteria. If the cell is not configured with a SUL or theWTRU does not support SUL communication for the frequency of the cell,then the WTRU may determine suitability of the cell using second cellsuitability criteria. Thereafter, the WTRU may select the cell based onthe determined suitability of the cell, and camp on the selected cell.

The first cell suitability criteria may include (e.g., utilize) a SULoffset specific to the cell. The second cell suitability criteria mayinclude (e.g., utilize) a non-SUL offset specific to the cell that isdifferent from the SUL offset. The WTRU may receive the SUL offsetand/or the non-SUL offset from the network. The WTRU may receive systeminformation from the cell, determine that the system informationincludes SUL configuration information, and determine that the cell isconfigured (e.g., or is not configured) with the SUL based on thereception of the SUL configuration information.

The WTRU may receive, from the cell, a system information block (SIB)comprising information relating to a second cell, and determinesuitability of the second cell based on the SIB. For example, if thesecond cell is configured with a SUL and the WTRU supports SULcommunication, then the WTRU may determine suitability of the secondcell using third cell suitability criteria (e.g., that includes anSUL-offset), whereas, if the second cell is not configured with a SUL orthe WTRU does not support SUL communication, then the WTRU may determinesuitability of the second cell using fourth cell suitability criteria(e.g., that includes a non-SUL-offset). The SIB may indicate whether thesecond cell supports SUL communication. The SIB may include anindication of a neighboring cell list with cell identifications (IDs) ofcells supporting SUL, and/or an indication of the SUL frequency of thecell supporting SUL.

BRIEF DESCRIPTION OF THE DRAWINGS

Like reference numerals in the figures indicate like elements.

FIG. 1A is a system diagram illustrating an example communicationssystem in which one or more disclosed embodiments may be implemented.

FIG. 1B is a system diagram illustrating an example wirelesstransmit/receive unit (WTRU) that may be used within the communicationssystem illustrated in FIG. 1A according to an embodiment.

FIG. 1C is a system diagram illustrating an example radio access network(RAN) and an example core network (CN) that may be used within thecommunications system illustrated in FIG. 1A according to an embodiment.

FIG. 1D is a system diagram illustrating a further example RAN and afurther example CN that may be used within the communications systemillustrated in FIG. 1A according to an embodiment.

FIG. 2 is a diagram of an example coverage map of a cell (e.g., a gNB).

FIG. 3 is a diagram of an example coverage map illustrating two cells.

FIG. 4 is a flowchart of an example cell selection/reselection procedurethat may be performed by a WTRU.

DETAILED DESCRIPTION

A detailed description of illustrative embodiments will now be describedwith reference to the various Figures. Although this descriptionprovides a detailed example of possible implementations, it should benoted that the details are intended to be exemplary and in no way limitthe scope of the application.

FIG. 1A is a diagram illustrating an example communications system 100in which one or more disclosed embodiments may be implemented. Thecommunications system 100 may be a multiple access system that providescontent, such as voice, data, video, messaging, broadcast, etc., tomultiple wireless users. The communications system 100 may enablemultiple wireless users to access such content through the sharing ofsystem resources, including wireless bandwidth. For example, thecommunications systems 100 may employ one or more channel accessmethods, such as code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA),orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tailunique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM(UW-OFDM), resource block-filtered OFDM, filter bank multicarrier(FBMC), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a RAN104/113, a CN 106/115, a public switched telephone network (PSTN) 108,the Internet 110, and other networks 112, though it will be appreciatedthat the disclosed embodiments contemplate any number of WTRUs, basestations, networks, and/or network elements. Each of the WTRUs 102 a,102 b, 102 c, 102 d may be any type of device configured to operateand/or communicate in a wireless environment. By way of example, theWTRUs 102 a, 102 b, 102 c, 102 d, any of which may be referred to as a“station” and/or a “STA”, may be configured to transmit and/or receivewireless signals and may include a user equipment (UE), a mobilestation, a fixed or mobile subscriber unit, a subscription-based unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watchor other wearable, a head-mounted display (HMD), a vehicle, a drone, amedical device and applications (e.g. remote surgery), an industrialdevice and applications (e.g. a robot and/or other wireless devicesoperating in an industrial and/or an automated processing chaincontexts), a consumer electronics device, a device operating oncommercial and/or industrial wireless networks, and the like. Any of theWTRUs 102 a, 102 b, 102 c and 102 d may be interchangeably referred toas a UE.

The communications systems 100 may also include a base station 114 aand/or a base station 114 b. Each of the base stations 114 a, 114 b maybe any type of device configured to wirelessly interface with at leastone of the WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to oneor more communication networks, such as the CN 106/115, the Internet110, and/or the other networks 112. By way of example, the base stations114 a, 114 b may be a base transceiver station (BTS), a Node-B, an eNodeB, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller,an access point (AP), a wireless router, and the like. While the basestations 114 a, 114 b are each depicted as a single element, it will beappreciated that the base stations 114 a, 114 b may include any numberof interconnected base stations and/or network elements.

The base station 114 a may be part of the RAN 104/113, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals on one or morecarrier frequencies, which may be referred to as a cell (not shown).These frequencies may be in licensed spectrum, unlicensed spectrum, or acombination of licensed and unlicensed spectrum. A cell may providecoverage for a wireless service to a specific geographical area that maybe relatively fixed or that may change over time. The cell may furtherbe divided into cell sectors. For example, the cell associated with thebase station 114 a may be divided into three sectors. Thus, in oneembodiment, the base station 114 a may include three transceivers, i.e.,one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and mayutilize multiple transceivers for each sector of the cell. For example,beamforming may be used to transmit and/or receive signals in desiredspatial directions.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g. radio frequency (RF),microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet(UV), visible light, etc.). The air interface 116 may be establishedusing any suitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104/113 and the WTRUs 102 a,102 b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 115/116/117 using wideband CDMA (WCDMA).WCDMA may include communication protocols such as High-Speed PacketAccess (HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-SpeedDownlink (DL) Packet Access (HSDPA) and/or High-Speed UL Packet Access(HSUPA).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement a radio technology such as Evolved UMTS TerrestrialRadio Access (E-UTRA), which may establish the air interface 116 usingLong Term Evolution (LTE) and/or LTE-Advanced (LTE-A) and/orLTE-Advanced Pro (LTE-A Pro).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement a radio technology such as NR Radio Access, which mayestablish the air interface 116 using New Radio (NR)

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c may implement multiple radio access technologies. For example, thebase station 114 a and the WTRUs 102 a, 102 b, 102 c may implement LTEradio access and NR radio access together, for instance using dualconnectivity (DC) principles. Thus, the air interface utilized by WTRUs102 a, 102 b, 102 c may be characterized by multiple types of radioaccess technologies and/or transmissions sent to/from multiple types ofbase stations (e.g. a eNB and a gNB).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.11 (i.e.,Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperabilityfor Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO,Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), InterimStandard 856 (IS-856), Global System for Mobile communications (GSM),Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and thelike.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, an industrialfacility, an air corridor (e.g. for use by drones), a roadway, and thelike. In one embodiment, the base station 114 b and the WTRUs 102 c, 102d may implement a radio technology such as IEEE 802.11 to establish awireless local area network (WLAN). In an embodiment, the base station114 b and the WTRUs 102 c, 102 d may implement a radio technology suchas IEEE 802.15 to establish a wireless personal area network (WPAN). Inyet another embodiment, the base station 114 b and the WTRUs 102 c, 102d may utilize a cellular-based RAT (e.g. WCDMA, CDMA2000, GSM, LTE,LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. Asshown in FIG. 1A, the base station 114 b may have a direct connection tothe Internet 110. Thus, the base station 114 b may not be required toaccess the Internet 110 via the CN 106/115.

The RAN 104/113 may be in communication with the CN 106/115, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. The data may have varying qualityof service (QoS) requirements, such as differing throughputrequirements, latency requirements, error tolerance requirements,reliability requirements, data throughput requirements, mobilityrequirements, and the like. The CN 106/115 may provide call control,billing services, mobile location-based services, pre-paid calling,Internet connectivity, video distribution, etc., and/or performhigh-level security functions, such as user authentication. Although notshown in FIG. 1A, it will be appreciated that the RAN 104/113 and/or theCN 106/115 may be in direct or indirect communication with other RANsthat employ the same RAT as the RAN 104/113 or a different RAT. Forexample, in addition to being connected to the RAN 104/113, which may beutilizing a NR radio technology, the CN 106/115 may also be incommunication with another RAN (not shown) employing a GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

The CN 106/115 may also serve as a gateway for the WTRUs 102 a, 102 b,102 c, 102 d to access the PSTN 108, the Internet 110, and/or the othernetworks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) and/orthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired and/or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another CN connected to one or more RANs, whichmay employ the same RAT as the RAN 104/113 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities (e.g. theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks). For example, the WTRU 102 c shown in FIG. 1A may be configuredto communicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram illustrating an example WTRU 102. As shownin FIG. 1B, the WTRU 102 may include a processor 118, a transceiver 120,a transmit/receive element 122, a speaker/microphone 124, a keypad 126,a display/touchpad 128, non-removable memory 130, removable memory 132,a power source 134, a global positioning system (GPS) chipset 136,and/or other peripherals 138, among others. It will be appreciated thatthe WTRU 102 may include any sub-combination of the foregoing elementswhile remaining consistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g. the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In an embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and/or receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

Although the transmit/receive element 122 is depicted in FIG. 1B as asingle element, the WTRU 102 may include any number of transmit/receiveelements 122. More specifically, the WTRU 102 may employ MIMOtechnology. Thus, in one embodiment, the WTRU 102 may include two ormore transmit/receive elements 122 (e.g. multiple antennas) fortransmitting and receiving wireless signals over the air interface 116

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as NR and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g. a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g. nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g. longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g. base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs and/or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, a Virtual Reality and/or Augmented Reality (VR/AR) device, anactivity tracker, and the like. The peripherals 138 may include one ormore sensors, the sensors may be one or more of a gyroscope, anaccelerometer, a hall effect sensor, a magnetometer, an orientationsensor, a proximity sensor, a temperature sensor, a time sensor; ageolocation sensor; an altimeter, a light sensor, a touch sensor, amagnetometer, a barometer, a gesture sensor, a biometric sensor, and/ora humidity sensor

The WTRU 102 may include a full duplex radio for which transmission andreception of some or all of the signals (e.g. associated with particularsubframes for both the UL (e.g. for transmission) and downlink (e.g. forreception) may be concurrent and/or simultaneous. The full duplex radiomay include an interference management unit 139 to reduce and orsubstantially eliminate self-interference via either hardware (e.g. achoke) or signal processing via a processor (e.g. a separate processor(not shown) or via processor 118). In an embodiment, the WRTU 102 mayinclude a half-duplex radio for which transmission and reception of someor all of the signals (e.g. associated with particular subframes foreither the UL (e.g. for transmission) or the downlink (e.g. forreception))

FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the CN 106.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and/or receive wireless signals from, the WTRU 102a.

Each of the eNode-Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the UL and/or DL, and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160 b, 160 c may communicate with one another over an X2 interface.

The CN 106 shown in FIG. 1C may include a mobility management entity(MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN)gateway (or PGW) 166. While each of the foregoing elements is depictedas part of the CN 106, it will be appreciated that any of these elementsmay be owned and/or operated by an entity other than the CN operator.

The MME 162 may be connected to each of the eNode-Bs 162 a, 162 b, 162 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 162 may provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM and/or WCDMA.

The SGW 164 may be connected to each of the eNode Bs 160 a, 160 b, 160 cin the RAN 104 via the S1 interface. The SGW 164 may generally route andforward user data packets to/from the WTRUs 102 a, 102 b, 102 c. The SGW164 may perform other functions, such as anchoring user planes duringinter-eNode B handovers, triggering paging when DL data is available forthe WTRUs 102 a, 102 b, 102 c, managing and storing contexts of theWTRUs 102 a, 102 b, 102 c, and the like.

The SGW 164 may be connected to the PGW 166, which may provide the WTRUs102 a, 102 b, 102 c with access to packet-switched networks, such as theInternet 110, to facilitate communications between the WTRUs 102 a, 102b, 102 c and IP-enabled devices.

The CN 106 may facilitate communications with other networks. Forexample, the CN 106 may provide the WTRUs 102 a, 102 b, 102 c withaccess to circuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. For example, the CN 106 may include,or may communicate with, an IP gateway (e.g. an IP multimedia subsystem(IMS) server) that serves as an interface between the CN 106 and thePSTN 108. In addition, the CN 106 may provide the WTRUs 102 a, 102 b,102 c with access to the other networks 112, which may include otherwired and/or wireless networks that are owned and/or operated by otherservice providers

Although the WTRU is described in FIGS. 1A-1D as a wireless terminal, itis contemplated that in certain representative embodiments that such aterminal may use (e.g. temporarily or permanently) wired communicationinterfaces with the communication network.

In representative embodiments, the other network 112 may be a WLAN

A WLAN in Infrastructure Basic Service Set (BSS) mode may have an AccessPoint (AP) for the BSS and one or more stations (STAs) associated withthe AP. The AP may have an access or an interface to a DistributionSystem (DS) or another type of wired/wireless network that carriestraffic in to and/or out of the BSS. Traffic to STAs that originatesfrom outside the BSS may arrive through the AP and may be delivered tothe STAs. Traffic originating from STAs to destinations outside the BSSmay be sent to the AP to be delivered to respective destinations.Traffic between STAs within the BSS may be sent through the AP, forexample, where the source STA may send traffic to the AP and the AP maydeliver the traffic to the destination STA. The traffic between STAswithin a BSS may be considered and/or referred to as peer-to-peertraffic. The peer-to-peer traffic may be sent between (e.g. directlybetween) the source and destination STAs with a direct link setup (DLS).In certain representative embodiments, the DLS may use an 802.11e DLS oran 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS)mode may not have an AP, and the STAs (e.g. all of the STAs) within orusing the IBSS may communicate directly with each other. The IBSS modeof communication may sometimes be referred to herein as an “ad-hoc” modeof communication

When using the 802.11ac infrastructure mode of operation or a similarmode of operations, the AP may transmit a beacon on a fixed channel,such as a primary channel. The primary channel may be a fixed width(e.g. 20 MHz wide bandwidth) or a dynamically set width via signaling.The primary channel may be the operating channel of the BSS and may beused by the STAs to establish a connection with the AP. In certainrepresentative embodiments, Carrier Sense Multiple Access with CollisionAvoidance (CSMA/CA) may be implemented, for example in in 802.11systems. For CSMA/CA, the STAs (e.g. every STA), including the AP, maysense the primary channel. If the primary channel is sensed/detectedand/or determined to be busy by a particular STA, the particular STA mayback off. One STA (e.g. only one station) may transmit at any given timein a given BSS

High Throughput (HT) STAs may use a 40 MHz wide channel forcommunication, for example, via a combination of the primary 20 MHzchannel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHzwide channel

Very High Throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz,and/or 160 MHz wide channels. The 40 MHz, and/or 80 MHz, channels may beformed by combining contiguous 20 MHz channels. A 160 MHz channel may beformed by combining 8 contiguous 20 MHz channels, or by combining twonon-contiguous 80 MHz channels, which may be referred to as an 80+80configuration. For the 80+80 configuration, the data, after channelencoding, may be passed through a segment parser that may divide thedata into two streams. Inverse Fast Fourier Transform (IFFT) processing,and time domain processing, may be done on each stream separately. Thestreams may be mapped on to the two 80 MHz channels, and the data may betransmitted by a transmitting STA. At the receiver of the receiving STA,the above described operation for the 80+80 configuration may bereversed, and the combined data may be sent to the Medium Access Control(MAC)

Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. Thechannel operating bandwidths, and carriers, are reduced in 802.11af and802.11ah relative to those used in 802.11n, and 802.11ac. 802.11afsupports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space(TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and16 MHz bandwidths using non-TVWS spectrum. According to a representativeembodiment, 802.11ah may support Meter Type Control/Machine-TypeCommunications, such as MTC devices in a macro coverage area. MTCdevices may have certain capabilities, for example, limited capabilitiesincluding support for (e.g. only support for) certain and/or limitedbandwidths. The MTC devices may include a battery with a battery lifeabove a threshold (e.g. to maintain a very long battery life)

WLAN systems, which may support multiple channels, and channelbandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include achannel which may be designated as the primary channel. The primarychannel may have a bandwidth equal to the largest common operatingbandwidth supported by all STAs in the BSS. The bandwidth of the primarychannel may be set and/or limited by a STA, from among all STAs inoperating in a BSS, which supports the smallest bandwidth operatingmode. In the example of 802.11ah, the primary channel may be 1 MHz widefor STAs (e.g. MTC type devices) that support (e.g. only support) a 1MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4MHz, 8 MHz, 16 MHz, and/or other channel bandwidth operating modes.Carrier sensing and/or Network Allocation Vector (NAV) settings maydepend on the status of the primary channel. If the primary channel isbusy, for example, due to a STA (which supports only a 1 MHz operatingmode), transmitting to the AP, the entire available frequency bands maybe considered busy even though a majority of the frequency bands remainsidle and may be available.

In the United States, the available frequency bands, which may be usedby 802.11ah, are from 902 MHz to 928 MHz. In Korea, the availablefrequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the availablefrequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidthavailable for 802.11ah is 6 MHz to 26 MHz depending on the country code

FIG. 1D is a system diagram illustrating the RAN 113 and the CN 115according to an embodiment. As noted above, the RAN 113 may employ an NRradio technology to communicate with the WTRUs 102 a, 102 b, 102 c overthe air interface 116. The RAN 113 may also be in communication with theCN 115.

The RAN 113 may include gNBs 180 a, 180 b, 180 c, though it will beappreciated that the RAN 113 may include any number of gNBs whileremaining consistent with an embodiment. The gNBs 180 a, 180 b, 180 cmay each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the gNBs 180 a, 180 b, 180 c may implement MIMO technology. For example,gNBs 180 a, 108 b may utilize beamforming to transmit signals to and/orreceive signals from the gNBs 180 a, 180 b, 180 c. Thus, the gNB 180 a,for example, may use multiple antennas to transmit wireless signals to,and/or receive wireless signals from, the WTRU 102 a. In an embodiment,the gNBs 180 a, 180 b, 180 c may implement carrier aggregationtechnology. For example, the gNB 180 a may transmit multiple componentcarriers to the WTRU 102 a (not shown). A subset of these componentcarriers may be on unlicensed spectrum while the remaining componentcarriers may be on licensed spectrum. In an embodiment, the gNBs 180 a,180 b, 180 c may implement Coordinated Multi-Point (CoMP) technology.For example, WTRU 102 a may receive coordinated transmissions from gNB180 a and gNB 180 b (and/or gNB 180 c).

The WTRUs 102 a, 102 b, 102 c may communicate with gNBs 180 a, 180 b,180 c using transmissions associated with a scalable numerology. Forexample, the OFDM symbol spacing and/or OFDM subcarrier spacing may varyfor different transmissions, different cells, and/or different portionsof the wireless transmission spectrum. The WTRUs 102 a, 102 b, 102 c maycommunicate with gNBs 180 a, 180 b, 180 c using subframe or transmissiontime intervals (TTIs) of various or scalable lengths (e.g. containingvarying number of OFDM symbols and/or lasting varying lengths ofabsolute time).

The gNBs 180 a, 180 b, 180 c may be configured to communicate with theWTRUs 102 a, 102 b, 102 c in a standalone configuration and/or anon-standalone configuration. In the standalone configuration, WTRUs 102a, 102 b, 102 c may communicate with gNBs 180 a, 180 b, 180 c withoutalso accessing other RANs (e.g. such as eNode-Bs 160 a, 160 b, 160 c).In the standalone configuration, WTRUs 102 a, 102 b, 102 c may utilizeone or more of gNBs 180 a, 180 b, 180 c as a mobility anchor point. Inthe standalone configuration, WTRUs 102 a, 102 b, 102 c may communicatewith gNBs 180 a, 180 b, 180 c using signals in an unlicensed band. In anon-standalone configuration WTRUs 102 a, 102 b, 102 c may communicatewith/connect to gNBs 180 a, 180 b, 180 c while also communicatingwith/connecting to another RAN such as eNode-Bs 160 a, 160 b, 160 c. Forexample, WTRUs 102 a, 102 b, 102 c may implement DC principles tocommunicate with one or more gNBs 180 a, 180 b, 180 c and one or moreeNode-Bs 160 a, 160 b, 160 c substantially simultaneously. In thenon-standalone configuration, eNode-Bs 160 a, 160 b, 160 c may serve asa mobility anchor for WTRUs 102 a, 102 b, 102 c and gNBs 180 a, 180 b,180 c may provide additional coverage and/or throughput for servicingWTRUs 102 a, 102 b, 102 c.

Each of the gNBs 180 a, 180 b, 180 c may be associated with a particularcell (not shown) and may be configured to handle radio resourcemanagement decisions, handover decisions, scheduling of users in the ULand/or DL, support of network slicing, dual connectivity, interworkingbetween NR and E-UTRA, routing of user plane data towards User PlaneFunction (UPF) 184 a, 184 b, routing of control plane informationtowards Access and Mobility Management Function (AMF) 182 a, 182 b andthe like. As shown in FIG. 1D, the gNBs 180 a, 180 b, 180 c maycommunicate with one another over an Xn interface.

The CN 115 shown in FIG. 1D may include at least one AMF 182 a, 182 b,at least one UPF 184 a,184 b, at least one Session Management Function(SMF) 183 a, 183 b, and possibly a Data Network (DN) 185 a, 185 b. Whileeach of the foregoing elements are depicted as part of the CN 115, itwill be appreciated that any of these elements may be owned and/oroperated by an entity other than the CN operator.

The AMF 182 a, 182 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N2 interface and may serve as acontrol node. For example, the AMF 182 a, 182 b may be responsible forauthenticating users of the WTRUs 102 a, 102 b, 102 c, support fornetwork slicing (e.g. handling of different PDU sessions with differentrequirements), selecting a particular SMF 183 a, 183 b, management ofthe registration area, termination of NAS signaling, mobilitymanagement, and the like. Network slicing may be used by the AMF 182 a,182 b in order to customize CN support for WTRUs 102 a, 102 b, 102 cbased on the types of services being utilized WTRUs 102 a, 102 b, 102 c.For example, different network slices may be established for differentuse cases such as services relying on ultra-reliable low latency (URLLC)access, services relying on enhanced massive mobile broadband (eMBB)access, services for machine type communication (MTC) access, and/or thelike. The AMF 162 may provide a control plane function for switchingbetween the RAN 113 and other RANs (not shown) that employ other radiotechnologies, such as LTE, LTE-A, LTE-A Pro, and/or non-3GPP accesstechnologies such as WiFi.

The SMF 183 a, 183 b may be connected to an AMF 182 a, 182 b in the CN115 via an N11 interface. The SMF 183 a, 183 b may also be connected toa UPF 184 a, 184 b in the CN 115 via an N4 interface. The SMF 183 a, 183b may select and control the UPF 184 a, 184 b and configure the routingof traffic through the UPF 184 a, 184 b. The SMF 183 a, 183 b mayperform other functions, such as managing and allocating WTRU/UE IPaddress, managing PDU sessions, controlling policy enforcement and QoS,providing downlink data notifications, and the like. A PDU session typemay be IP-based, non-IP based, Ethernet-based, and the like.

The UPF 184 a, 184 b may be connected to one or more of the gNBs 180 a,180 b, 180 c in the RAN 113 via an N3 interface, which may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between the WTRUs 102a, 102 b, 102 c and IP-enabled devices. The UPF 184, 184 b may performother functions, such as routing and forwarding packets, enforcing userplane policies, supporting multi-homed PDU sessions, handling user planeQoS, buffering downlink packets, providing mobility anchoring, and thelike.

The CN 115 may facilitate communications with other networks. Forexample, the CN 115 may include, or may communicate with, an IP gateway(e.g. an IP multimedia subsystem (IMS) server) that serves as aninterface between the CN 115 and the PSTN 108. In addition, the CN 115may provide the WTRUs 102 a, 102 b, 102 c with access to the othernetworks 112, which may include other wired and/or wireless networksthat are owned and/or operated by other service providers. In oneembodiment, the WTRUs 102 a, 102 b, 102 c may be connected to a localData Network (DN) 185 a, 185 b through the UPF 184 a, 184 b via the N3interface to the UPF 184 a, 184 b and an N6 interface between the UPF184 a, 184 b and the DN 185 a, 185 b.

In view of FIGS. 1A-1D, and the corresponding description of FIGS.1A-1D, one or more, or all, of the functions described herein withregard to one or more of: WTRU 102 a-d, Base Station 114 a-b, eNode-B160 a-c, MME 162, SGW 164, PGW 166, gNB 180 a-c, AMF 182 a-ab, UPF 184a-b, SMF 183 a-b, DN 185 a-b, and/or any other device(s) describedherein, may be performed by one or more emulation devices (not shown).The emulation devices may be one or more devices configured to emulateone or more, or all, of the functions described herein. For example, theemulation devices may be used to test other devices and/or to simulatenetwork and/or WTRU functions.

The emulation devices may be designed to implement one or more tests ofother devices in a lab environment and/or in an operator networkenvironment. For example, the one or more emulation devices may performthe one or more, or all, functions while being fully or partiallyimplemented and/or deployed as part of a wired and/or wirelesscommunication network in order to test other devices within thecommunication network. The one or more emulation devices may perform theone or more, or all, functions while being temporarilyimplemented/deployed as part of a wired and/or wireless communicationnetwork. The emulation device may be directly coupled to another devicefor purposes of testing and/or may performing testing using over-the-airwireless communications.

The one or more emulation devices may perform the one or more, includingall, functions while not being implemented/deployed as part of a wiredand/or wireless communication network. For example, the emulationdevices may be utilized in a testing scenario in a testing laboratoryand/or a non-deployed (e.g. testing) wired and/or wireless communicationnetwork in order to implement testing of one or more components. The oneor more emulation devices may be test equipment. Direct RF couplingand/or wireless communications via RF circuitry (e.g. which may includeone or more antennas) may be used by the emulation devices to transmitand/or receive data.

Examples provided herein do not limit applicability of the subjectmatter to other wireless technologies, e.g., using the same or differentprinciples as may be applicable.

The term network may refer to one or more gNBs that may (e.g. in turn)be associated with one or more Transmission/Reception Points (TRPs) orother node in a radio access network (RAN).

A cell may be configured (e.g. in NR) with a supplementary uplink (SUL).An SUL may extend the coverage of a WTRU that may be operating in highfrequency, for example, by switching the UL to a lower band, e.g., whenthe WTRU may be far from a gNB. An SUL may be modeled (e.g. in NR) as acell with a DL carrier that may be associated with multiple (e.g. two)separate UL carriers. For example, the DL carrier may be associated witha regular UL (RUL) (e.g., which may be in a high frequency band where aDL carrier may be located) and an SUL (e.g., which may be in a frequencyband that is lower than the frequency band of the RUL).

An SUL may be configured for a PCell (e.g. in an NR standalone mode) anda PSCell (e.g. in NR-NR DC or in dual connectivity between LTE and NR,which may be termed NSA mode or EN-DC).

A WTRU may perform initial access to a cell, for example, using RUL orSUL. An SUL configuration may be broadcast in minimum SI by a cell. AWTRU may select an SUL for initial access, for example, when (e.g. onlywhen) a DL quality of a serving cell may be below a threshold.

Multiple (e.g. three) operating modes may be possible for SUL when aWTRU is in RRC Connected. An RRC may (e.g. in a first operating mode)configure a WTRU with multiple (e.g. two) ULs, for example, a full ULconfiguration and a sounding reference signal (SRS) configuration. AWTRU may (e.g. in this mode of operation) use a fully configured ULconfiguration (e.g. for all control and data transmission in theuplink), but may transmit SRS on another (e.g. non-fully configured)uplink. RRC reconfiguration (e.g. to provide a full UL configuration fora different carrier) may be used, for example, to switch between UL databetween different ULs. An RRC may (e.g. in a second operating mode)configure multiple ULs (e.g. fully configured ULs), for example twofully configured ULs. Signaling, such as MAC CE or DCI, may be definedto enable a WTRU to switch between UL configurations. An RRC may (e.g.in a third operating mode) configure multiple (e.g. two) ULs, which may(e.g. both) be used, for example, when a PUSCH transmission for a singleserving cell may not occur simultaneously for multiple ULs.

SUL may be supported in RRC. In carrier aggregation, an UL carrier (e.g.each UL carrier) may be associated with and scheduled by a (e.g. single)DL carrier in the same band.

A UL carrier that may be used in RRC Procedures may be associated withan (e.g. each) RRC state. Rules may be associated with initial access toa cell having SUL. Selection of a UL carrier for an (e.g. each) RRCprocedure may, for example, depend on factors beyond or different thanDL quality.

An SUL may be in a frequency band that may be different than a DLcarrier. A UL carrier of a cell (e.g. in LTE) may be in the samefrequency as a DL carrier. For example, when performing response drivenpaging, a paging indicator response performed on SUL may not be used bya network (NW) to select a DL beam to transmit paging record.

A WTRU may have a different coverage depending on use of RUL or SUL. Oneor more procedures (e.g., RLF, SCG failure, re-establishment, etc.) maytake into consideration a UL carrier that is being used for the one ormore procedures, e.g., to be consistent with their intended purpose.

One or more procedures may limit use of an SUL by WTRUs. It may bepreferable to reduce the number of carriers to configure as SUL (e.g.given that they may also be normal UL carriers for cells at lowfrequency), for example, even when (e.g. all) DL carriers in the highfrequency band may be configured with an SUL.

A WTRU may be configured to perform cell selection and/or reselectionbased one or more criterions in NR systems with SUL. For cell selectionand/or cell-reselection, the existing criterion in E-UTRAN may becalculated taking into account the DL RSRP and RSRQ with offsetcompensation for higher priority cells. A WTRU's transmission power maybe taken into account with the parameter Pcompensation. A cell selectioncriterion S in normal coverage may be fulfilled in E-UTRAN when:

Srxlev>0 AND Squal>0

where:

Srxlev=—Q _(rxlevmeas)−(Q _(rxlevmin) +Q_(rxlevminoffset))−Pcompensation−Qoffset_(temp)

Squal=Q _(qualmeas)−(Q _(qualmin) +Q _(qualminoffset))−Qoffset_(temp)

Pcompensation=max(P _(EMAX1) −P _(PowerClass),0)(dB)

A WTRU's Tx power (PPowerClass) lower than the value allowed in the cell(PEMAX1) may result in a greater PCompensation value (e.g., making ithard to select the cell). A certain correspondence between UL and DLtransmission may be assumed in LTE bands. In mmWaves, however, the ULtransmission may be impacted (e.g., strongly impacted) by thepropagation environment. In such scenarios, the foregoing equation maynot be sufficient for cell-selection and/or reselection.

FIG. 2 is a diagram of an example coverage map 200 of a cell 202 (e.g.,a gNB). In high frequencies (e.g., high new radio (NR) frequencies), ULcoverage of the cell 202 may be significantly less than DL coverage ofthe cell 202. The cell 202 may include a Supplementary UL (SUL), whichfor example, may be a lower frequency than the regular UL (RUL) and thedownlink (DL) of the cell 202. The RUL and SUL may be paired with eachDL of a cell (e.g., an SCell). A WTRU 204 may camp on the SUL whenRSRP<SUL_threshold (e.g., when RSRP of the RUL is <SUL_threshold). Thenetwork may deploy the SUL unevenly in an area (e.g., some cells mayinclude SULs, while other cells may not). Support of SUL by the WTRU 204may be defined per band combination (e.g., per frequency). The WTRU 204may not support SUL configured for a specific cell (e.g., the WTRU 204may not support SUL for the frequency of the SUL of the cell). If theWTRU 204 uses only DL measurements, the WTRU 204 may camp in a cell withpoor uplink coverage, leading to unnecessary handovers orre-establishments upon connection. The examples provided herein may, forexample, be used to ensure that a WTRU camps on a cell having the bestcombination of downlink and uplink coverage in an environment with mixedSUL/non-SUL support.

FIG. 3 is a diagram of an example coverage map 300 illustrating twocells 302, 304. The cell 302 may not support SUL, while the cell 304 maysupport SUL (e.g., as illustrated by the area of no UL coverage 308).The WTRU 306 may be located proximate to the boundary between the cell302 and the SUL coverage area of cell 304. Thresh_1 may indicate athreshold (e.g., cell quality threshold, such as RSRP) that the WTRU 306uses when determining whether to stay camped within cell 302 or reselectto the SUL of cell 304. SUL Threshold may indicate a threshold (e.g.,cell quality threshold, such as RSRP) that the WTRU 306 uses whendetermining whether to communicate with the cell 304 on the RUL orswitch to communicating via the SUL of cell 304.

FIG. 4 is a flowchart of an example cell selection/reselection procedure400 that may be performed by a WTRU. A WTRU that supports SUL may usemodified cell selection and/or cell reselection procedures to prioritizecell(s) that utilize SUL in band combinations supported by the WTRU overa cell that does not support SUL. For example, for cells that utilizeSUL in a band combination supported by the WTRU, the WTRU may receivebiasing/offset information for one or more of the S-criteria evaluation(e.g., a suitability offset for SUL cells), neighbor cell measurementtriggering threshold(s) (e.g., SmeasThres), neighbor cell reselectionranking criteria (e.g., Rn), and/or serving cell reselection rankingcriteria (Rs). The biasing/offset information may be provided in systeminformation. The biasing/offset information may be used (e.g., onlyused) by WTRUs that support SUL in the band combination (e.g.,transparent to network for IDLE mode WTRUs). The biasing/offsetinformation may be used to favor SUL cells during cell selection andreselection.

For example, in 402, 404, 410, and 412, the WTRU may determine selectionor reselection parameters based on Serving DL Cell quality (e.g., RSRP)and/or SUL support (e.g., on the SUL frequency) of the WTRU. In 406,408, 414, 416, and 418, the WTRU may perform an evaluation and/orselection/reselection procedure, for example, using values determinedduring 402, 404, 410, and/or 412. In 404-408, the WTRU may bedetermining whether to measure other cells and trigger ranking andreselection. In 412-418, the WTRU may be performing cell ranking andreselection decisions. In 414-416, the neighbor cells to consider forreselection may be further dependent on the same condition as 406-408.

The WTRU may determine whether one or more cells (e.g., camped cell,camping target, neighbor cells, etc.) utilize a SUL. For instance, at402, the WTRU may determine whether a camped cell supports SUL, while at410, the WTRU may determine whether one or more neighbor and/orpotential reselection cells support SUL. The WTRU may determine whetherthe WTRU supports the SUL (e.g., the band combination) on the campedcell at 404 (e.g., based on system information and WTRU capabilities).If so, the WTRU may use SUL specific values for S and SmeasThres (e.g.,S(SUL), SmeasThres (SUL)), for example, when performing a reselectionanalysis. If not, the WTRU may use RUL specific values for S andSmeasThres (e.g., S(RUL), SmeasThres (RUL)), for example, whenperforming a reselection analysis.

Similarly, when determining SUL support on neighbors and target cells at410, the WTRU may determine whether the WTRU supports SUL on a NeighborCell and/or whether the DL_RSRP<Thresh_1. If the WTRU supports SUL onthe cell and if DL_RSRP<Thresh_1, then the WTRU may use an offset value(e.g., Rn′=Rn+Offset and Rs′=Rs+Offset), for example, when performing anevaluation and/or selection/reselection analysis. If the WTRU doessupport SUL on the cell and/or if DL_RSRP≥Thresh_1, then the WTRU mayuse Rn′=Rn and Rs′=Rs, for example, when performing an evaluation and/orselection/reselection analysis. As noted above, in 406, 408, 414, 416,and 418, the WTRU may perform an evaluation and/or selection/reselectionprocedure, for example, using values determined during 402, 404, 410,and/or 412.

Examples of idle/inactive state procedures for the use of SUL areprovided herein. For example, cell suitability criteria may take intoaccount the presence of SUL/RUL configuration. Cell suitability criteriamay apply to one or more (e.g. all) procedures that may utilize cellsuitability (e.g. camping). Cell suitability criteria may depend onwhether a cell may be configured with a SUL, and may utilize one or moreof a threshold, an offset, or a criterion (e.g. Squal or similar) forcell quality of a suitable cell. For example, the threshold, the offset,and/or the criterion for an SUL may be different than those of a RUL. AWTRU may receive an offset or compensation parameter, which may be usedto determine cell suitability criteria, for example, depending whetherthe cell may be configured with SUL and/or depending whether the WTRUsupports the SUL feature. Alternatively or additionally, a WTRU mayutilize multiple (e.g. two) different cell suitability criteriacalculations. For example, a WTRU may select a first calculation todetermine suitability for a cell that transmits SUL configurationinformation in system information. The WTRU may select a secondsuitability criteria calculation when determining suitability criteriafor a cell that does not transmit an SUL configuration in systeminformation, or, for example, when the WTRU may not support the SULfeature.

Cell selection in idle may be implemented considering SUL/RUL. In anexample, a WTRU may consider the quality of the UL transmission in acell in its cell selection criterions. For example, a WTRU maydifferentiate the cells configured with SUL for a suitabilityevaluation. The WTRU may determine the suitability evaluation based onone or more of the following. For example, suchdifferentiation/evaluation may: be dependent on the frequency carrier ofthe RUL and paired DL; take into account the configuration of SUL (e.g.,if applicable); be captured in the UL Pcompensation used in theevaluation of the cell selection criterion; be evaluated through a newcell selection criterion that takes into account the propagationcharacteristic of the cell (e.g., as well as the configuration of SUL ifapplicable); and/or may take into account the parameters for cellselection associated to prioritize or otherwise favor one of the twoconfigurations (e.g., RUL versus SUL).

In an example, additional cell selection-reselection criterion may beintroduced to evaluate the impact of the propagation for the WTRU uplinktransmission and the necessity of selecting a cell with configured SUL(e.g., if applicable). For example, any combination of the followingthree conditions may be used to select a given cell:

Srxlev>0,Squal>0, and/or Stxlev>0

where:

Stxlev=Q _(rxlevmeas) —Q _(rxlevthreshold) +Q _(SUL-offset);

-   -   Q_(rxlevmeas) is the measured cell RX level value (RSRP);    -   Q_(rxlevthreshold) is the configured RSRP threshold received by        the WTRU in RMSI; and    -   Q_(SUL-offset) is an offset to the signaled Q_(rxlevthreshold)        (e.g., Q_(SUL-offset) may be used in the Stxlev evaluation to        adjust its value when SUL and associated power compensation are        configured in the cell); and    -   When SUL is not configured, Q_(SUL-offset)=0.

Additional cell selection-reselection criterion may be used whenselecting a cell with configured SUL (e.g., if applicable). APcompensation value for a cell takes into account the configuration ofSUL. In mmWaves, even if the maximum power of transmission of the WTRUequals the maximum allowed power in a cell, the UL coverage may not besufficient for the WTRU to reach its serving transmission point. In thecalculation of Pcompensation, a frequency offset Q_(freq-offset) may beintroduced to capture the propagation conditions in the UL of WTRUs inhigher frequencies when SUL is configured and not.

Pcompensation=max(P _(EMAX1) −P _(PowerClass) +Q _(freq-offset),0)(dB)

where:

-   -   P_(EMAX1) is the maximum TX power level a WTRU may use when        transmitting on the uplink in the cell (dBm);    -   P_(PowerClass) is the maximum RF output power of the WTRU (dBm)        according to the WTRU power class; and    -   Q_(freq-offset) is the offset to the signaled P_(PowerClass)        taken into account in the Pcompensation evaluation as a result.

The value of Q_(freq-offset) may be a function of the cell frequencycarrier and the configuration (e.g., or lack of configuration) of theSUL. This is may (e.g., intentionally) make it harder for/less likelythat the WTRU to select cells with a poor estimated UL coverage and noSUL configured, while cells with configured SUL will have a higherchance to be selected by the WTRU.

In an example, a cell selection criteria for a SUL may be based on thefollowing:

Srxlev>0,Squal>0, and/or Stxlev>α

where:

-   -   Srxlev may evaluate the quality of the downlink transmission        (e.g., the Pcomensation of the uplink is not included in the        calculation).        Srxlev=Q_(rxlevmeas)−(Q_(rxlevmin)+Q_(rxlevminoffset))−Qoffset_(temp)    -   Stxlev may evaluate the quality of the uplink transmission        (e.g., separately). Stxlev=Pcompensation where Pcompensation=max        ((P_(EMAX1)−P_(PowerClass)),        (P_(EMAX1_SUL)−P_(PowerClass_SUL))). The P_(Power_Class) value        may be different depending on whether the WTRU is operating in        two different RF chains (such as, for example, one for        frequencies above 6 GHz and the other below 6 GHz). The        threshold a may be broadcasted in system information and/or may        be configurable by the network.

The WTRU may receive an additional value of P_(EMAX1). P_(EMAX1_SUL) mayapply for the SUL carrier. P_(EMAX1_SUL) may be received in a SIB.P_(EMAX1_SUL) may be used in the Pcompensation calculation as themaximum TX power level a WTRU to use when transmitting on the SULcarrier.

A WTRU may consider one of more factors when performing cell reselectionin IDLE. For example, a WTRU may consider the support of a SUL by a cellin its cell reselection rules. In an example, the WTRU may prioritize acell having an SUL configuration (e.g., or providing access via an SULover a cell without SUL) when deciding whether to camp on a cell and/orwhether to measure intra/inter-frequency neighbor cells. Such decisionmay be dependent on one or more of the following, that suchprioritization may, for example: be limited to certain types of WTRUs ora WTRU with certain capabilities (e.g., MTC WTRU vs normal WTRU); belimited to WTRUs in a certain state, such as the WTRU's current batterypower, temporary capability restrictions, etc.; be dependent on the areain which the WTRU is currently roaming, or be dependent on the WTRU'sPLMN; and/or be determined based on rules derived from information inSIBs broadcast by the cell(s), or in an RRCConnectionRelease orRRCConnectionReject message.

In an example, a WTRU may, when camped on an cell, be provided withdifferent values of intra frequency search thresholds (e.g.,S(intraSearchP), S(intraSerachQ), etc.) depending on whether the servingcell has an SUL or not. If a WTRU is camped on a cell with a SUL, theWTRU may use cell reselection parameters associated with SUL. If a WTRUis camped on a cell without SUL, the WTRU may use cell reselectionparameters associated with a cell without SUL. Such difference may allowa WTRU to initiate intra-frequency measurements more quickly (e.g., toaccount for reduced UL coverage) when a cell does not support SUL. Thecell reselection parameters may be area specific (e.g., and not cellspecific). Therefore, the cell reselection parameters associated with acell with SUL and the cell reselection parameters associated with a cellwithout SUL may be broadcast in system information.

A WTRU may apply an additional offset to the cell ranking criteria fordetermination of the best cell, for example, depending on whether thecell has an SUL or not. The offset may be provided in systeminformation. A WTRU may be provided with different values ofQoffset/Qoffset_(Temp) for RUL and SUL cells, and apply such offset tothe cell ranking for a cell (e.g., serving or neighbor) depending onwhether such cell supports SUL or not.

The offset applied for cell-ranking may be applied to the cell rankingcriteria depending on the measured cell RX level (RSRP) of the DL in thecell and/or the presence of an SUL configured for that cell. Forexample, the WTRU may apply an offset to a cell when it is configuredwith SUL and/or may apply such offset when (e.g., only when) the RXlevel (RSRP) or similar is below a threshold. The offset (e.g., apositive offset) applied to cells configured with SUL may be a functionof the received RSRP.

A cell reselection criterion may be implemented based on speed. Forexample, when a high mobility level and/or a medium mobility level isdetected, a WTRU may prioritize cells with configured SUL over cellsoperating with RUL alone (e.g., since an associated beamformed systemmay be less robust to mobility).

The offset temporarily applied to a cell (Qoffset_(temp)) may be scaledby an additional factor. This factor may (e.g., also) be a function ofthe RSRP measurement quantity used in the cell ranking criterion forneighboring and/or serving cells. For example, a cell having a high RSRPand no configured SUL may not be prioritized above a cell having a lowerRSRP and configured SUL (and/or the cell with SUL may be prioritizedover the cell without SUL).

When a high mobility or a medium mobility is detected by a WTRU, apositive bias to the serving cell signal strength (Q_(Hyst)) may bereduced by a configurable factor sf-High, which may correspond to a“Speed dependent ScalingFactor for Q_(hyst)”. In an example involvinghigh mobility, if the serving cell is supporting SUL, the WTRU may needto attenuate this bias reduction. For example, a bias reduction may bereduced by a configurable factor sf-High_SUL, which may correspond to an“Additional speed dependent ScalingFactor for Q_(hyst)”. Further, insome examples, a timer for cell reselection may be scaled by anadditional factor to increase the time of reselection if the servingcell is configured with SUL.

A WTRU may receive SUL related cell-selection parameters in a systeminformation block (SIB). The WTRU may determine whether frequenciescarriers and cells support SUL (e.g., to be able to characterize thequality of the target cell, including the quality of the SUL carrier).For example, the WTRU may receive SUL related cell-selection parametersdefining the configuration of SUL in neighboring cells in the SIB of thecamping cell. The WTRU may identify/differentiate the cells supportingSUL and apply the associated SUL related cell-selection parameters inthe various selection/reselection criteria evaluations. These values maybe one or more of the following: received as a neighboring cell list(e.g., with cell Ids of the various cells supporting SUL); received as aone bit information list which is mapped to the neighboring cell listreceived in a SIB (e.g., SIB5) for cell-specific selection parameters;received as an indication associated to the frequency carrier bandconfiguration; based on stored information from previously detectedcells; and/or requested by the WTRU when proximity to a cell supportingSUL may be detected.

A WTRU may receive in a SIB (e.g., SIB3) the common parameters for intraand inter-frequency cell reselection. Additionally, the WTRU may receivea SUL support neighboring list (e.g., in a SIB) containing the cell Idsof the neighboring cells supporting SUL. A WTRU may receive in a SIB(e.g., SIB5) the SUL related cell-selection parameters. The WTRU mayreceive a list (interFreqNeighCellList_SUL) that indicates the cellswith SUL related cell-selection parameters for which the WTRU may applythe SUL specific cell selection parameters. The WTRU may receive in aSIB (e.g., SIB5) a list mapped to IntraFreqNeighCellList indicating, forexample, 0 for the neighboring cells not supporting SUL and 1 for thecells of the list supporting SUL, and/or a field indicating whichcell-specific parameters are applied if the neighboring cell supportsSUL.

The WTRU may keep an SUL support list of previously visited cells withSUL configured, and, for example, may use an autonomous search functionto detect at least the previously visited cells whose Cell ID andassociated PLMN identity may be in the WTRU's SUL support whitelist. Thedetection of proximity based on an autonomous search function may allowa WTRU to send a ProximityIndication_SUL message to indicate that theWTRU is entering or leaving the proximity of one or more cellssupporting SUL. This function may be enabled if (e.g., only if) the WTRUis one or more of: high, experiencing a high attenuation in thedownlink, and/or is in a high mobility state. If the WTRU detects one ormore suitable cells in the SUL_Support_List, then the WTRU may reselectto one of the detected cells (e.g., irrespective of the frequencypriority of the cell the WTRU is currently camped on (e.g., if theconcerned SUL cell is the highest ranked cell on that frequency)).

A WTRU may maintain a SUL configuration in an RRC inactive state. A WTRUmay maintain its dedicated RUL/SUL configuration while in anRRC_INACTIVE state. Such maintenance of the configuration may enable theWTRU to perform UL transmission while remaining in RRC_INACTIVE, and mayavoid a number of WTRUs in RRC_INACTIVE state all using the same SULconfiguration (e.g., and the same pool of RACH resources). Rules may berequired for the WTRU to determine when to release its RUL/SULconfiguration and use the RUL/SUL configuration in the RMSI instead. Insome examples, the WTRU may maintain the RUL/SUL configuration, andrelease such configuration upon expiry of a timer.

The WTRU may release the RUL/SUL configuration upon occurrence of amobility event, for example, reselection to another cell; reselection toanother cell associated with a different RAN area; reselection toanother cell which does not support SUL; and/or transmission of aperiodic RAN Location Area Updated (RLAU) (e.g., to the same cell orwhen it is transmitted to a different cell).

The WTRU may release the RUL/SUL configuration upon a resume procedureto a cell (e.g., if it provides a new configuration for the RUL/SUL). AWTRU may use the stored dedicated configuration for access related toresume, and may replace the stored configuration with a new dedicatedconfiguration provided (e.g., in the resume message or reconfigurationfollowing the resume procedure).

A WTRU may perform SUL procedures relating to paging and initial access.A WTRU may determine an uplink carrier in which to perform initialaccess, for example, in response to paging, e.g., based on informationprovided in a paging message. A WTRU may receive an indication toperform initial access on an SUL or RUL. For example, the WTRU mayreceive the indication to perform initial access on a SUL or RUL in apaging message. Configured parameters for access on SUL/RUL may beprovided in system information and/or stored in a dedicatedconfiguration (e.g. INACTIVE state configuration). A WRTU may receive apaging record for which the signaled WTRU ID matches the WTRU's IDLEstate ID. A WTRU (e.g. in RRC_IDLE) may receive an indication to performinitial access on an SUL or RUL. A WTRU may initiate an initial accessprocedure, for example, using the stored system information associatedwith the SUL/RUL configuration (e.g. RACH preamble/resources, carrierfrequency, etc.). A WTRU may initiate an initial access procedure, forexample, using stored information on an uplink carrier that may beindicated in the paging message. A WTRU (e.g. in RRC_INACTIVE) mayobtain a SUL/RUL configuration, for example, from system information orby dedicated RRC signaling while the WTRU was in RRC_CONNECTED, whichmay be stored during transition to RRC_INACTIVE.

A WTRU may determine a UL carrier (e.g. SUL/RUL), for example, based ona combination of information, such as information that may be providedin a paging record in addition to one or more of the following: (i)measured quality (e.g. RSRP, RSRQ, etc.) of a DL carrier of a cell inwhich a paging may be (e.g. may have been) received; (ii) WTRUspeed/velocity; (iii) WTRU battery power; (iv) WTRU maximum ULtransmission power, and/or (v) other information.

Regarding WTRU speed/velocity, in an example, if the mobility of theuser is fast (or above a threshold), the WTRU may select the SULcarrier. This may be more reliable and may allow the WTRU to transmit inwider beams associated to the SUL (e.g., instead of narrower beamsassociated to RUL resulting in often changes of beams).

Regarding WTRU battery power, a WTRU may select the UL carrier thatwould lead to the lowest power usage, for example, as follows: if theresult of received power control plus the power adjustment for SUL(e.g., to compensate the difference between a pathloss estimate for theSUL frequency and the path loss estimated on the DL carrier in the cell)for UL transmission in SUL is a threshold higher than the received powercontrol for RUL, the WTRU may select RUL carrier; inversely, if thereceived power control for RUL is a threshold higher than the result ofthe received power control plus the power adjustment for SUL, the WTRUmay select the SUL carrier.

Regarding WTRU maximum UL transmission power, if the result of receivedpower control plus the power adjustment for SUL is higher than themaximum output power of the WTRU, the WTRU may select the RUL carrier.

A WTRU may choose an indicated carrier (e.g. SUL or RUL), for example,when one or more conditions (e.g. for any of the above quantities) maybe met. A condition may, for example, be based on the value of aquantity being above/below a threshold, which may be provided, forexample, in system information, RRC configuration, and/or in a pagingmessage, etc. The NW may manage a load of UL resources on SUL/RUL whiletaking into account the type of data to be transmitted to a WTRU in theDL (e.g. short data transmission, low latency data requiring a highreliability acknowledgement, etc.).

In an example, a WTRU may receive an RSRP threshold in the pagingmessage that the WTRU may use to decide whether to perform initialaccess in response to paging on the SUL or the RUL. For example, if thecell quality is below the threshold provided in the paging message, theWTRU may perform initial access on the SUL, otherwise, it may performinitial access on the RUL. Such thresholds received in the pagingmessage may override or be prioritized over any other thresholdsreceived in system information from the cell.

A WTRU may determine the UL to use for access based on a combination ofthe forgoing without such information provided in the paging message,such as, for example, WTRU battery power or WTRU maximum UL transmissionpower.

A WTRU may use multiple thresholds for decision criteria. For example, aWTRU may be provided with multiple RSRP thresholds for deciding betweeninitial access on SUL or RUL. A (e.g., each) threshold may be associatedwith a different access type, or similar factor relating to the accessby the WTRU. The WTRU may determine the uplink on which to performinitial access (SUL or RUL) by identifying the appropriate thresholdbased on the access type. The WTRU may perform access on the SUL if theDL cell quality is below the associated threshold, or may perform accesson RUL if the DL cell quality is above the associated threshold. A WTRUmay associate a threshold (e.g., each of the thresholds) with one ormore of the following factors: a WTRU type, or WTRU class, which may bestatically defined for a WTRU (e.g. MTC WTRU) and may be defined basedon the WTRU's capability; an access category, or service type defined atthe higher layers (e.g., NAS or application layer); different connectionestablishment causes (e.g. tracking area update, DL data, resume fromINACTIVE state, RAN area update); logical channel/priority of data inthe WTRU buffer at the time of access, for example, for access fromINACTIVE state; and/or amount of data in a buffer (e.g., for a specificlogical channel) being above or below a threshold.

A WTRU may initiate access on SUL or RUL where the described factors maynot be associated with a threshold. For example, a WTRU may initiate(e.g., may always initiate) access for a high priority logical channel(e.g., URLLC) on SUL, regardless of the threshold. In another example,the WTRU may (e.g., may always) perform RLAU on the RUL. Such specialcases may be enabled by specific rules, or the WTRU may receive aspecial value of the threshold (e.g., negative or positive infinity)which may allow it to follow the described behavior.

A WTRU may perform (e.g. one or more portions of) an initial access, forexample, based on a network indication. For example, the WTRU mayreceive from a network one or more indications of which parts of aninitial access may be performed in SUL/RUL. The WTRU may (e.g. based onan indication in a paging message), for example, perform PRACHtransmission on an RUL/SUL and may transmit MSG3 on the SUL/RUL. A WTRUmay, for example, determine or assume a grant that may be received inMSG2 for UL transmission of MSG3 references resources in the carrierindicated in the paging message for MSG3 transmission. For example, thegrant in MSG2 may reserve resources on the SUL, if the paging indicatedthat MSG3 should be transmitted on SUL, while it may reserve resourceson RUL if the paging message indicated that MSG3 should be transmittedon RUL. The WTRU may, (e.g. based on an indication in a paging message)perform PRACH transmission on a RUL/SUL and/or may transmit MSG3 on acarrier that may be (e.g. explicitly) indicated in MSG2 (e.g. with a CIFor similar flag in MSG2 MAC CE).

During initial access, a NW may not have quality information (e.g. SRStransmission by a WTRU) to appropriately select a UL (e.g. SUL or RUL).A WTRU may, for example, provide UL selection information during aninitial access procedure. Information that may be provided may include,for example, one or more of the following: (i) measured quality (e.g.RSRP, RSRQ, etc.) of a DL carrier of a cell; (ii) WTRU speed/velocity,and/or (iii) logical channel ID of data that triggered the access. TheWTRU may provide this information to a network, for example, by one ormore of the following ways: (i) in an RRC message or MAC CE that may beincluded with MSG3, and/or (ii) implicitly (e.g. based on selection of aRACH preamble/resource). The WTRU may be configured (e.g. in systeminformation or by dedicated RRC signaling) to use a subset of RACHpreamble/resources, for example, when WTRU speed may be above athreshold. The NW may utilize information (e.g. provided by a WTRU), forexample, to select an appropriate UL (e.g. SUL or RUL) to configure theWTRU. The WTRU may receive (e.g. in MSG4 of an initial access/resumeprocedure) a configuration for a UL, which may include a UL to use SULand/or RUL, for example, for subsequent communication with the NW.

When performing response driven paging, a paging indicator responseperformed on SUL may not be used by the NW to select a DL beam totransmit paging record. A WTRU may transmit beam information on an SUL.For example, the WTRU may provide beam information of the DL beam on anon-beamformed UL carrier (e.g. the SUL) to the NW, for example, duringan initial access procedure. A WTRU may, for example, identify a beam,beam index or synchronization signal block (SSB) index that may beassociated with correct reception of a paging indicator message. A WTRUmay provide an identifier to a NW, for example, during a RACH procedurethat may be performed on an SUL (e.g. a non-beamformed frequency).Information may be provided, for example, using one or more of thefollowing procedures.

A WTRU may provide an identifier using (e.g. explicitly using) a datatransmission or data part that may be appended to a PRACH preambletransmission. A WTRU may select a PRACH preamble/resource that may beassociated with an identifier. A WTRU may, for example, be configured(e.g. through system information or dedicated RRC signaling) with amapping of a PRACH preamble/resource on a non-beamformed UL carrier(e.g. SUL) for a given beam index on the DL (e.g. beamformed carrier). AWTRU may select a PRACH preamble/resource pair based on a configuredmapping.

A WTRU may delay transmission of a PRACH preamble, for example, by anamount of time that may be related to the index decoded. A WTRU may, forexample, be configured (e.g. through system information or dedicated RRCsignaling) with a (e.g. specific) time delay to use for a (e.g. each)SSB beam index. A WTRU may, for example, select a time delay (e.g.number of subframes to wait) for transmission of a PRACH preamble, e.g.,by a hardcoded amount that may relate (e.g. directly) to an index (e.g.index 1=1*x subframes, index 2=2*x subframes, etc.).

During handover, a WTRU may determine which carrier is RUL/SUL. A WTRUmay receive configuration for multiple (e.g. two) UL carriers in ahandover (HO) command (e.g. one corresponding to SUL and anothercorresponding to RUL). The network may provide an indication to indicatewhich configuration applies to which carrier. A WTRU may apply (e.g.subsequent) procedures/actions (e.g. during or after completion of an HOcommand), for example, depending whether an HO may be performed to a SULor RUL. Knowledge of SUL/RUL may be derived by a WTRU that may, forexample, use one or more of the following: (i) (e.g. explicit)indication in an HO command; (ii) presence/absence of beam-relatedinformation in an L1/L2 configuration and/or ARFCN. In an example (e.g.of ARFCN), a WTRU may consider (e.g. all) frequencies below a referenceARFCN to be an SUL. A WTRU may determine a configuration associated withan SUL to be the one with the lower value of ARFCN, for example, when aWTRU is provided with separate full configurations for SUL and RUL, or afull configuration for one carrier and a partial configuration foranother carrier.

There are various procedures that may vary depending whether a WTRUcompleted an HO command on an RUL or a SUL. These procedures include,for example, one or more of the following: (i) UL carrier selection foran HO (e.g. behavior discussed herein may be subject to knowledgewhether a carrier is SUL/RUL, which may be determined as describedherein); (ii) HO failure procedure (e.g. a WTRU may perform a differentaction upon HO failure that may depend whether an HO may be firstperformed to an SUL or RUL); (iii) RLF/S-RLF procedure (e.g. a WTRU mayperform different actions upon triggering RLF/S-RLF, or specific formsof RLF/S-RLF, for example, depending whether an HO may be performed viaan SUL or RUL); (iv) re-establishment procedure (e.g., in the case offailed HO) or in the case of RLF following HO; (v) resume procedurefollowing suspend; (vi) UL data and/or UL RRC routing and/or (vii) asystem information request. The WTRU may receive an indication of theone or more procedures described above as part of an HO command and/orwhile the WTRU is in RRC Connected.

A WTRU may receive from a network uplink carrier selection information(e.g., SUL and/or RUL) in an HO command, and may select the uplink onwhich to perform initial access based on the information. For example,the WTRU may be provided with a carrier to use (e.g. SUL or RUL), e.g.,to perform initial access during HO. An indication may be an explicitindicator of which carrier to use. A network may, for example, provide aUL configuration for SUL and RUL (e.g. in an HO command or in systeminformation). A WTRU may perform initial access during HO with aconfiguration of an indicated carrier.

The WTRU may perform HO to a carrier that may contain (e.g. in the HOcommand) necessary information to perform initial access. The WTRU mayreceive from the network a (e.g. single) full configuration in an HOcommand (e.g. SUL or RUL). The WTRU may perform initial access on acarrier that may be associated with the configuration. The configurationmay, for example, consist of initial access parameters (e.g.dedicated/common RACH resources). The configuration may (e.g. further)include configuration for a UL carrier (e.g. L1 configuration, L2configuration, etc.), for example, to use during operation inRRC_CONNECTED mode. The WTRU may (e.g. in addition to a single fullconfiguration) receive a (e.g. an additional) reduced configuration foranother UL carrier (e.g. RUL or SUL), which may contain, for example, anARFCN and SRS configuration for UL SRS transmissions following an HOcommand. The WTRU may (e.g. in this case) select a carrier on which afull configuration may be provided to perform initial access and mayconfigures (e.g. only) SRS on another carrier.

The WTRU may perform initial access during HO to a carrier (e.g.SUL/RUL. The WTRU may operate or be configured with UL operation duringand/or following HO completion in another carrier (RUL/SUL). The WTRUmay (e.g. in this case) receive a RACH configuration for an SUL and afull configuration (e.g. L1, L2) for an RUL, or vice versa.

A WTRU may determine a carrier (e.g. SUL or RUL) on which to perform HO,for example, based on the state of the WTRU in a source cell (e.g. priorto an HO command). The WTRU may be configured with multiple (e.g. two)separate configurations (e.g. RUL and SUL) in a source cell but may beconfigured to use (e.g. only) a (e.g. single) configuration during thetime of reception of an HO command. The WTRU may, for example, determineor assume the same UL (e.g. RUL or SUL) may (e.g. should) be used in atarget cell. The WTRU may perform initial access to a target cell usingthe UL carrier. Alternatively or additionally, the WTRU may beconfigured with (e.g., only) SUL in the source cell, and the resultingselection by the WTRU of the UL for initial HO may be to select the SULin the target cell (e.g., even though the WTRU may be provided bothconfigurations in the HO command). The WTRU may, for example, (e.g.further) determine or assume a configuration in an HO command (e.g. tobe used in a target cell) is associated with the same type of UL carrier(e.g. RUL or SUL) as the last configuration in the source cell. The WTRUmay (e.g. additionally or alternatively) be configured to use bothSUL/RUL in a source cell (e.g. according to NW scheduling). The WTRU may(e.g. in this case) use another procedure (e.g. as described herein) toselect between SUL/RUL during HO. The WTRU may receive the configurationinformation for SUL and RUL in an HO command.

The WTRU may receive a common SUL configuration for source and targetcells. The WTRU may determine or assume an actual SUL configuration of atarget cell is the same as an SUL configuration of a source cell. TheWTRU may make a determination or assumption, for example, based on oneor more of the following: (i) a configuration; (ii) a relation of atarget cell ID to a source cell ID, and/or (iii) an indication in an HOcommand (e.g. an explicit indication or implicitly (e.g. by the absenceof an SUL configuration). The WTRU may utilize an SUL configuration of asource cell during an HO command and following HO, possibly until theWTRU is reconfigured with a new SUL configuration (e.g. throughdedicated RRC signaling or during acquisition of system information).

The WTRU may determine an uplink (SUL and/or RUL) based on WTRUdetermined factors. A WTRU may be provided with a full configuration forSUL and RUL. A WTRU may select a carrier for initial access for HO basedon one or more conditions that may be measured/determined at the WTRU,for example, such as one or more of (e.g. any combination of) thefollowing: (i) DL cell quality, such as RSRP, RSRQ, etc. (e.g. incomparison with a threshold that may be configured or hardcoded); (ii)WTRU speed/velocity, (e.g. in comparison with a threshold that may beconfigured or hardcoded); (iii) WTRU battery power (e.g. in comparisonwith a threshold that may be configured or hardcoded); (iv) WTRU maximumUL transmission power (e.g. in comparison with a threshold that may beconfigured or hardcoded); (v) logical channel ID(s) of data that may bepending in WTRU buffers and/or (vi) beam on which WTRU may have receivedan HO command.

In an example (e.g. of logical channel ID(s) of data that may be pendingin WTRU buffers), a WTRU may perform UL access to an SUL, for example,when there is data in one or more WTRU buffers that may correspond to a(e.g. certain) set of logical channels that indicates a (e.g. certain)priority or delay criticality. A (e.g. minimum) priority level may beconfigured by a NW (e.g. in dedicated or broadcast signaling).

In an example (e.g. of a beam on which a WTRU may have received an HOcommand), a WTRU may be configured with a set of beam IDs for initialaccess to a target cell, and a correspondence of beam ID to SUL or RUL.A WTRU may determine a UL carrier to use, for example, based on a beamID in which an HO command was received. A configuration may be targetcell specific.

A WTRU may select one of a set of target cells based on SUL/RULcriteria. The WTRU may be provided with a target cell configuration forone or more cells, e.g., in an HO command. The WTRU may perform initialaccess to a target cell for an HO, for example, based on measurementsperformed a (e.g. each) candidate target cell, e.g., at reception of anHO command. The WTRU may perform an HO to a target cell that may have abetter DL cell measurement (e.g. RSRP) at the time of an HO command. TheWTRU may (e.g. in the context of SUL/RUL selection) select a target cellfor which the selection of RUL/SUL may result in a selection of the RULby the WTRU.

A load on an SUL may be reduced, for example, when an HO may prioritizeto cells for which a WTRU may not require use of an SUL at the time ofan HO. A decision by a WTRU (e.g. compared to an NW decision) may bemore accurate (e.g. since measurement may be performed at the time of anHO command) and may be combined with other factors (e.g. WTRU specificfactors) to which an NW may not have access (e.g. speed, beaminformation, etc.).

The WTRU may use a timer-based fallback to a SUL during an HO procedure.The WTRU may initiate an HO procedure to an RUL and may fallback toperforming an HO to a SUL, e.g., following a condition. For example, theWTRU may initiate an HO to an RUL. The WTRU may be configured with atimer that determines when to fallback to an SUL. The WTRU may start atimer at reception of an HO command. The timer may be started, forexample, (e.g. only) when a WTRU selects RUL for initial access duringan HO. The WTRU may perform an HO to a RUL while a timer may be running.The WTRU may attempt an HO to a target via an SUL, for example, uponexpiration of a timer. The timer may or may not be equivalent to an HOfailure timer (e.g. T304).

In an (e.g. additional or alternative) example (e.g. which may be usedin combination with another example), a WTRU may be (e.g. further)configured with a second timer. The second timer may dictate an amountof time that a WTRU may attempt an HO on an SUL before an HO failure maybe declared. The WTRU may start a timer, for example, when it initiatesfallback to an SUL. The WTRU may attempt an HO to a target cell, forexample, via an SUL until a second timer may be running. An HO failuremay be declared, for example, upon expiration of the second timer.

The WTRU may implement fallback to contention-based (common) resourcesduring HO. For example, following failure to perform HO on dedicated(CFRA) resources provided by the NW, the WTRU may fallback tocontention-based random access resources, and may select such resourceson either SUL or RUL. The WTRU may base its selection decision onwhether the dedicated resources were provided on the SUL or the RUL.

The WTRU may select the same UL (SUL or RUL) as the UL in which itreceived the dedicated resources for CFRA. For instance, if the WTRUreceives dedicated resources on the RUL/SUL, and HO fails on thededicated resources, the WTRU may fallback on contention-based resourceson the RUL/SUL. The WTRU may (e.g., may always) use the UL resourcesassociated with the SUL, assuming such resources are provided by thenetwork. The WTRU may use the RUL resources if the SUL resources are notprovided. The WTRU may determine the UL carrier to use based on themeasured DL quality at the time of the HO or HO failure on the dedicatedresources. For example, if the WTRU is provided with common resources onboth SUL and RUL in the HO command, the WTRU may perform fallback to theSUL resources when the DL cell quality is below a threshold, and mayperform fallback to the RUL otherwise. In the described criteria, HOfailure on dedicated (CFRA) resources may include a failed RACHprocedure or attempt, or it may include a beam associated with thededicated RACH resource being below a configured threshold.

The WTRU may base fallback to SUL on beam suitability and/orprioritizing contention-free access. The WTRU may fallback to attemptingan HO on an SUL (e.g. following initial attempts on an RUL), forexample, when there may no longer be any beams on an RUL that maysatisfy a (e.g. specific) suitability criteria.

Alternatively or additionally, the WTRU may (e.g. first) perform an HOon one or more dedicated resources (e.g. beams) of an RUL, e.g., as maybe provided by an HO command, for example, when one or more of thosebeams may be measured to be above an associated threshold (e.g. providedin an HO command). The WTRU may (e.g. prior to an HO attempt or duringHO attempts to a target on dedicated RACH resources such as beams),determine that a quality of (e.g. all) dedicated RACH resources fallbelow a configured threshold. The WTRU may initiate an HO procedure onan SUL (e.g. using an SUL configuration). The WTRU may (e.g. further)perform fallback to an SUL (e.g. only), for example, when (e.g. oncondition that) it may be provided with a dedicated RACH configuration(e.g. contention-free resources) on the SUL.

In an (e.g. additional or alternative) example, a WTRU may (e.g. first)perform an HO on one or more dedicated resources (e.g. beams) on an RUL(e.g. provided in an HO command), for example, when one or more of thebeams have a quality above a threshold. A WTRU may (e.g. when a beamdoes not have a quality above a threshold) use a beam in a commonconfiguration (e.g. associated with contention based random access) ofan RUL, for example, when one or more beams/resources may have a qualityabove a (e.g. the same or different) threshold. A WTRU may (e.g. then)fallback to performing initial access for an HO on an SUL, for example,when no beams/resources on an RUL (e.g. common or dedicated) may have aquality above a threshold.

A WTRU may request a change of a UL carrier based on one or morefactors. A WTRU may request that an NW change a UL. The WTRU may beconfigured to utilize a (e.g. only one) UL (e.g. an RUL). A WTRU (e.g.as configured) may request that a network change its UL to anothercarrier (e.g. SUL).

Initiation of a request or change of a UL may, for example, be based onone or more conditions, such as one or more of the following: (i) DLquality of a cell; (ii) speed of a WTRU; (iii) current WTRU batterypower, and/or (iv) the arrival of high-priority data. In an example, aWTRU may request or change a UL (e.g. change from an RUL to an SUL) atsome time after receiving a reconfiguration command, for example, when ameasured quality of a DL may be below a threshold (e.g. configured by anetwork). In an example, a WTRU may request or change a UL (e.g. changefrom an RUL to an SUL), for example, when the WTRU speed may (e.g.start) to exceed a network-configured threshold. In an example, a WTRUmay request or change a UL (e.g. change from an RUL to an SUL), forexample, when remaining WTRU battery power may be below a threshold(e.g. configured by a network).

In an example, a WTRU may request or change a UL (e.g. change from anRUL to an SUL), for example, when a packet may arrive on a (e.g.certain) logical channel or radio bearer at a WTRU, where a priority ofthe packet may be above a (e.g. certain) priority level. A WTRU maytrigger a change in a UL (e.g. RUL to SUL), for example, when a new datapacket may arrive at an SDAP/PDCP layer that may be associated with a(e.g. specific) QoS level or may be mapped to a (e.g. specific) radiobearer. A QoS level and/or radio bearer (e.g. which may trigger a changeprocedure) may be configured by a network.

In an (e.g. additional or alternative) example (e.g. which may be usedin combination with another example), a WTRU may (e.g. further) beprovided with a time validity for an SUL configuration and an associatedcondition. A WTRU (e.g. upon receipt of a conditional configuration),may start a timer and may evaluate one or more conditions, for example,when the timer is running. A WTRU may (e.g. upon expiration of a timer)delete a received configuration and stop evaluation of one or moreassociated conditions.

WTRU behavior may adapt based on a triggering condition. For example,the WTRU may (e.g. in foregoing examples) inform lower layers of a needto switch to an SUL. A WTRU may (e.g. further) initiate a procedure inlower layers that may be associated with informing an NW of a UL switch.Upper layer(s) may initiate one or more lower-layer procedures such as,for example, one or more of the following: (i) initiation of a RACHprocedure or RACH-like procedure in an SUL; (ii) transmission of an RRCmessage on a currently configured UL (e.g. RUL); (iii) transmission on aPUCCH (e.g. SR or other indication) on an SUL (e.g. when resources maybe configured), and/or (iii) transmission of an RRC message on a masternode (e.g. eNB/gNB), for example, when a WTRU may be configured with DCand/or when RUL/SUL configurations may be associated with transmissionon a secondary node (SN) (e.g. gNB).

A WTRU may transmit a switch indication to a network. An indication maybe, for example, an RRC message transmitted to the network. Anindication may provide information such as, for example, one or more ofthe following: (i) an indication of a switch request (e.g. todifferentiate from a RACH procedure for other purposes); (ii) a causefor the switch (e.g. condition satisfied causing the switch); (iii)measurements that may be associated with the switch (e.g. measurementsof DL quality, WTRU speed, etc.), and/or (iv) expected/determinedduration for utilization of an SUL and subsequent switch back to an RUL(or vice versa).

For example, the WTRU may transmit a switch indication message in MSG3of a RACH procedure or RACH-like procedure to an SUL, e.g., to indicatea switch to SUL to a network. In an (e.g. additional or alternative)example, a WTRU may transmit a switch indication message as an RRCmessage on an RUL, or as an RRC message to an MN (e.g. when a switch toSUL may be associated with an SN).

The WTRU may include data and/or signaling in MSG3 (included in theswitch indication). In an example, the WTRU may wait for reception of aconfirmation by the NW and may transmit the data and/or signaling (e.g.,which may have triggered transmission of the switch indication over theSUL) once the WTRU is switched to the SUL (by DCI or RRC configuration).

The WTRU may receive a switch indication confirmation. For example, aWTRU may (e.g. following transmission of a switch indication message)receive a switch confirmation from a network. A switch confirmation mayconfirm use of an SUL by a WTRU or refuse a request. A WTRU may (e.g.upon receiving a positive confirmation) initiate utilization of an SUL(e.g. for transmission of data). A WTRU may (e.g. further) receive (e.g.in a switch indication confirmation message) a configuration (e.g.L1/L2) that may be used on an SUL. Alternatively or additionally, theWTRU may receive a switch indication confirmation message in MSG4 of aRACH procedure that may be performed on an SUL.

A UL change/reconfiguration may be conditional. An NW based decision forchange (e.g. from RUL to SUL) may be based (e.g. primarily) on WTRUtransmission of an SRS and DL signaling (e.g. RRC, MAC/DCI) forreconfiguration, which may not handle fading/blocking that occurs fasterthan an SRS period, and which may affect successful transmission ofwhere URLLC data may need to be sent in a UL.

A WTRU may change a UL, for example, based on a configured condition.For example, a WTRU may be provided with a configuration (e.g. in adedicated RRC or system information) of an SUL and may initiate ortrigger a switch from usage of an RUL to usage of the SUL whileoperating in RRC_CONNECTED mode, for example, a time after reception ofthe reconfiguration or switch message. A switch may occur, for example,as a result of one or more conditions being satisfied at a WTRU.Conditions may, for example, be the same as conditions for requesting aswitch from a network. A WTRU may apply a switch or reconfiguration, forexample, (e.g. only) when it may (e.g. does) occur within a configuredtime period following reception of a switch or reconfiguration. A WTRUmay (e.g. further) receive a condition as part of a configuration of anSUL. A WTRU may utilize an RUL for a period of time during which acondition associated with a switch may be satisfied. A switch from SULto RUL may be initiated, for example, when a condition may no longer besatisfied. A WTRU may (e.g. additionally or alternatively) stayconfigured on an SUL for a predefined or configured period of time,after which, the WRTU may move back to utilizing a previousconfiguration of an RUL. A WTRU may (e.g. additionally or alternatively)move back to utilizing an RUL, for example, based on a differentcondition that may be related to an initial condition for utilization ofan SUL (e.g. successful transmission of a high priority packet).

The WTRU may be configured with uplink semi-persistent scheduling acrossSUL/RUL. The WTRU may be configured with fast relocation of UL SPS froman RUL to an SUL, and vice versa. A WTRU may be configured with asemi-persistent schedule configuration applicable to RUL and SUL. In anexample, a WTRU may be configured with a (e.g. single) SPS-config thatmay be associated with RUL and SUL. In an (e.g. additional oralternative) example, a WTRU may be configured with multiple (e.g. two)separate SPS-configs (e.g. a first SPS-config may be associated with RULand a second SPS-config may be associated with SUL).

A WTRU may be (e.g. further) configured to determine whether a UL-grantis associated with an SPS-config is applicable on an RUL and/or SUL. Inan example, a WTRU may be (e.g. explicitly) signaled that one or moreconfigured SPS grants are applicable on a (e.g. specific) UL carrier(e.g. RUL or SUL).

A WTRU may be configured to perform (e.g. fast) relocation of a UL SPSfrom an RUL to an SUL and vice versa, for example, based on implicitrules or explicit command. Relocation may refer to suspending an SPSconfig that is applicable for a first UL carrier and applying anSPS-config that is applicable for a second UL carrier.

In an example, a WTRU may be configured to suspend an SPS-config that isapplicable for an RUL and apply an SPS-config that is applicable for anSUL, for example, upon receiving a reconfiguration command, e.g., in anMAC CE, RRC signaling or L1 signaling.

In an (e.g. additional or alternative) example, a WTRU may autonomouslyperform a relocation, for example, when a UL SPS is configured for anSUL and/or one or more preconfigured conditions are satisfied.Conditions may include, for example, determining a quality of a DL belowa threshold, DL path-loss below a threshold, when UL SPS retransmissionsexceed a predetermined threshold, etc. Conditions, which may bepreconfigured, may include other trigger conditions that may beapplicable for an SUL switch.

A WTRU may be configured, for example, to use SPS UL grants on RUL andSUL, e.g., for increased reliability/diversity. A WTRU may applyduplication or alternating transmissions, for example, using apredefined hopping pattern across an SUL and an RUL.

The WTRU may confirm SPS relocation. A WTRU may be configured toacknowledge (e.g. in an explicit case) or indicate (e.g. in an implicitcase) an SPS relocation, for example, by transmission of a MAC CE, RRCsignaling or L1 signaling (e.g. SRS transmission) on a relocated ULcarrier. A WTRU may transmit an acknowledgement on an SUL carrier, forexample, upon receiving an SPS relocation command from RUL to SUL.

A WTRU may be configured for SPS resources and/or to receive a dynamicgrant. A WTRU may be configured with SPS resources (Type 1 or Type 2resources) on either or both ULs. A WTRU may receive (e.g., furtherreceive) a dynamic grant on the same transmission interval for one ofthe two uplinks configured in the WTRU.

A dynamic grant may enable transmission redundancy. In an example, aWTRU that receives an UL grant on the non-SPS carrier (e.g., a dynamicUL grant on SUL when SPS is configured on RUL or vice versa) may performduplicate transmission of the data (e.g., transport block) on both theSUL and RUL. A WTRU may be configured with one or a set of logicalchannels on which such duplication behavior should be applied. A WTRUmay perform such duplication behavior if, for example, there is datapending for such logical channels at the time of reception of suchdynamic grant, and if not, may otherwise cancel the SPS grant.

A dynamic grant may enable cancellation of a set of grants. In anexample, a WTRU that receives an UL grant on the non-SPS carrier maycancel the current grant as well as a number of upcoming SPS grants. Thedynamic grant received by the WTRU (which results in cancellation of theSPS grants) may need to be sent for the same transmission interval asone of the SPS grants. The number of SPS grants to be cancelled may bedetermined in one or more of the following: (i) the WTRU may cancel anumber of SPS grants indicated (by some value) in the dynamic grantitself ((e.g. value in the DCI message). After skipping or cancellingthe signaled number of grants on the UL carrier configured with SPS, theWTRU may start using the grants based on the same configuration); (ii)the WTRU may cancel all SPS grants until the reception of NW signalingfrom the NW that re-enables the SPS grants.

In an example, the NW signaling that re-enables the SPS grants may be inthe form of a dynamic grant on the UL with the configured SPS resources.For example, the WTRU with SPS configured on the RUL may receive adynamic grant for the SUL on the same transmission interval as one ofthe SPS grants. The WTRU may cancel that SPS grant, as well as allfurther SPS grants on the RUL until it receives another dynamic grantfor UL resources on the RUL again.

In an example, the NW signaling that re-enables the SPS grants may be inthe form of a DCI message used specifically to re-activate the SPSresources. This may be a DCI used for SPS activation (e.g., DCIaddressed to CS-RNTI) or may be some other dedicated NW signaling. Forexample, the WTRU with SPS configured on RUL may receive a dynamic grantfor the SUL on the same transmission interval as one of the SPS grants.The WTRU may cancel that SPS grant, as well as all further SPS grants onRUL until it receives an SPS activation message (e.g., DCI messageaddressed to CS-RNTI) to re-activate the previously configured SPSgrant.

A WTRU may cancel all SPS grants for as long as the WTRU's measured DLRSRP is below a threshold. The WTRU may indicate to the NW through someUL transmission (e.g., RACH or SRS like) when the DL RSRP may move abovethe threshold and the WTRU resumes using the SPS grants.

A WTRU's described behavior may depend on which UL (SUL or RUL) the SPSresources are configured for. A WTRU's described behavior may (e.g., mayalso) depend on the type of SPS resources (e.g., Type 1 CS or Type 2CS).

In an example, where a dynamic grant cancels a set of grants, if the SPSresources are configured on the RUL and the dynamic grant is for theRUL, the WTRU may perform cancellation of the SPS grants as described.If the SPS resources are configured on the SUL and the dynamic grant isprovided for the RUL, the WTRU may cancel (e.g., only) a single grant(as in the case of LTE).

In an example, where a dynamic grant cancels a set of grants, thetrigger for re-enabling or re-starting the SPS grants may depend onwhether the SPS grants are associated with Type 1 CS (e.g., RRC definesthe grant and no PDCCH is needed) or Type 2 CS (e.g., RRC defines theperiodicity of the CS grant and PDCCH addressed to CS/SPS-RNTI activatesthe CS grant). With Type 1, the WTRU may re-enable the SPS grantsfollowing cancellation (e.g., when it receives a dynamic grant for an ULon RUL). With Type 2, the WTRU may re-enable the SPS grants followingcancellation (e.g., when it receives a DCI addressed to CS/SPS-RNTI thatactivates the SPS).

Various mechanisms may be used to assist with routing and reliability ofcontrol signaling (e.g. RRC signaling).

A WTRU may be configured to perform duplication of RRC messages on anRUL and an SUL. The WTRU RRC layer may inform lower layers that an (e.g.a specific) RRC message passed to lower layers may (e.g. should) beduplicated on an RUL and an SUL. The WTRU may determine to performduplication of RRC messages on the RUL and SUL based on one or more ofthe following: (i) the WTRU is configured with an RUL and an SUL; (ii)the WTRU is configured with an RUL and an SUL, and both are active (e.g.PUSCH scheduling on either UL is possible); (iii) DL cell quality of acell in which an RUL and an SUL is configured is below or above athreshold; (iv) an RRC message is a specific type (e.g. measurementreport), and/or (v) measurements associated with a measurement reportfollow a condition for duplication of the messages.

The WTRU (e.g., the RRC layer) may indicate when a condition forduplication is no longer be enabled. The lower layers of the WTRU mayperform duplication for (e.g. all) RRC messages during a time whenduplication is enabled. For example, the lower layers may performduplication by transmitting in an RUL and an SUL, for example, whenscheduled on either carrier. The lower layers may (e.g. additionally oralternatively) perform a procedure to notify a network of a need forresources in both the RUL and SUL (e.g. RACH procedure, SR procedure,etc.), for example, when the WTRU is configured on both but active ononly one, or when the WTRU is configured on one of the RUL or the SUL.

The WTRU and/or the network may switch the UL path for RRC signaling.The WTRU may be configured to switch the UL path (from RUL to SUL, orvice versa) associated with transmission of RRC signaling. For example,the WTRU may be configured to transmit RRC signaling on one of the twoULs at a given time, and may be configured to change the UL for suchmessage based on a certain event. The change of UL may be applicable to(e.g., only to) RRC signaling. The change of UL may be applicable to(e.g., only) a specific type(s) of RRC message, for example, one or moreof the following: a measurement report; a measurement report triggeredby a certain type of event; and/or a measurement report satisfyingcertain conditions on the measurement quality, triggering time, etc.

In an example, the WTRU may change the UL for transmission of RRCmessages by transmitting the RRC message when (e.g., only when)scheduled on the SUL, or when the NW switches the WTRU to the SUL. TheWTRU may proactively request an UL switch to the other UL in order totransmit the RRC message on the other UL. The WTRU may transmit a switchindication (e.g., RACH on SUL) when requiring a change in the UL for RRCsignaling. The WTRU may (e.g., may further) indicate that such switchapplies (e.g., only) to RRC signaling.

The WTRU may determine that an RRC message should be transmitted on adifferent UL (e.g., switch from RUL to SUL) based on one or more of thefollowing conditions: (i) a measured DL quality of the cell goes below(e.g., or above) a threshold; (ii) a WTRU speed is below (e.g., orabove) a threshold; (iii) a maximum UL transmission power is below(e.g., or above) a threshold; (iv) a WTRU battery power is below (e.g.,or above) a threshold; (v) the RRC message is transmitted on SRB1/SRB2;and/or (vi) the RRC message is of a specific type (e.g., measurementreport) with specific criteria (e.g. associated with a specificmeasurement event).

A UL path may be selected for RRC signaling in dual connectivity (DC).The WTRU may be configured with any form of DC (e.g. NR-NR DC, EN-DC,etc.). The WTRU may decide a UL path for an RRC message, for example,based on a DL quality of a PSCell or SCell on an SN. The WTRU may (e.g.when DL quality on an SN may be acceptable) transmit an RRC message toan SN. The WTRU may (e.g. otherwise) transmit an RRC message to an MN,for example, when a DL quality on an SN may not be acceptable.

The WTRU may be configured with an SRB3 and may split SRB1/2 (e.g.anchored at the MN). The WTRU may transmit RRC messages on SRB3, forexample, when a measured DL quality of an SN PSCell may be above a (e.g.configured) threshold. The WTRU may transmit RRC messages on SRB1/2, forexample, when a measured DL quality of an SN PSCell may be below athreshold. The WTRU may (e.g. when transmitting an RRC message onSRB1/2) encapsulate an NR RRC message in an LTE RRC message, forexample, when the WTRU is configured with an EN-DC. The WTRU may (e.g.further) apply a determination (e.g. only) for RRC messages that may(e.g. normally) be transmitted on SRB3 (e.g. measurement reports relatedto measurement configuration configured by an NR SN).

In an (e.g. additional or alternative) example, a WTRU (e.g. configuredwith SRB3 and split SRB1/2) may transmit an RRC message (e.g. intendedfor an SN) on SRB1 (e.g. to an MN via a transparent container), forexample, when the WTRU is configured with an RUL in an SN or has (e.g.only has) an RUL activated in the SN, and the DL quality of the SN (e.g.PSCell) is below a threshold configured for RUL usage (e.g. a thresholdto determine whether an RUL or SUL may be used for initial access oranother threshold to determine whether an RUL or SUL may be chosen).

The WTRU and/or the network may have Radio link failure (RLF) andassociated error procedures for a SUL. The WTRU may be configured tosend beam recovery requests, for example upon detecting problems withone or more uplink and/or downlink beams. For example, a beam failuremay be detected at the WTRU (e.g., by the lowers layers). The WTRU mayinitiate a random access (RA) procedure for beam failure recovery (BFR).An UL transmission in a regular frequency carrier may not permit theWTRU to transmit the preamble associated to the selected referencesignal successfully to the gNB.

The WTRU may (e.g., when performing random access for BFR) apply one ormore of the following procedures: perform the BFR first in RUL and thenin SUL; perform the BFR in SUL (e.g., immediately after beam failure isdeclared if SUL is configured); select a UL based on the configurationof dedicated RACH resources in either uplink (e.g., utilize an UL inwhich the WTRU has a valid dedicated RACH configuration); and/ortransmit the preamble in the RUL and receive grants for both ULs.

The WTRU may perform the BFR first in RUL and then in SUL. In such anexample, performing BFR in the SUL may be used as a fallback procedureafter a certain condition is reached on RUL. For example, one or more ofthe following may occur when performing BFR in the RUL that may triggerthe WTRU to perform BFR in the SUL: a specific timer may expire; acertain number of attempts may be reached; and/or a certain power oftransmission may be reached.

In an example where the WTRU selects a UL based on the configuration ofdedicated RACH resources in either uplink, one or more of following mayoccur: the WTRU may first perform contention-free RA (CFRA) in the UL(e.g., RUL or SUL) where dedicated RACH resources areconfigured/available; the WTRU (e.g., if unsuccessful) may perform thecontention-based RA (CBRA) in RUL. If CFRA resources are configured inboth uplinks, a priority may be given and the WTRU may perform CFRA inorder of priority.

A purpose of a beam failure recovery request procedure may be toindicate to the serving gNB of a new SSB or CSI-RS when beam failure isdetected on the serving SSB(s)/CSI-RS(s). A transmission in theconfigured SUL may not allow the gNB to identify the strongest beamwhere the preamble is transmitted. An indication to the NW may benecessary to determine which SSB or CSI-RS in DL may (e.g., should) beused in the DL transmissions.

An indication to the NW (e.g., gNB) may be handled by one or more of thefollowing: the configured preambles in SUL may be mapped to SSB orCSI-RS of the same cell; the WTRU may indicate to the NW which DL beamis the strongest (e.g., by transmitting the beam ID associated to thestrongest SSB or CSI-RS in msg3); and/or the WTRU may send an RRCmessage to the gNB on SUL indicating the strongest DL beam or containingthe associated measurement results.

The WTRU may be configured with dedicated RACH resources mapped to SSBsand/or CSI-RS resources in the cell. The WTRU may select a preamble inSUL that may be associated to a specific SSB or/CSI-RS beam in which itmay receive the RAR and msg4.

The WTRU may transmit the preamble in a beam in the regular frequencycarrier, and may receive (e.g., in msg2) a grant for both SUL and RUL.If dedicated RACH resources are configured in only one uplink, the WTRUmay transmit the preamble in the carrier where the dedicated resourcesare configured. If dedicated RACH resources are configured in bothuplinks, the WTRU may attempt CFRA on a suitable beam associated to adedicated RACH resource in RUL (if available) and fallback to SUL (e.g.,only if one of the defined conditions are met). If dedicated RACHresources are configured in both uplinks, the WTRU may attempt on SUL(e.g., if no suitable beam associated to a dedicated RACH resource inRUL is available), before fallback to CBRA in the RUL.

The WTRU may be configured with a threshold for suitability criteria ofthe beams associated to CSI-RS or SSB. If RSRP associated to any beam isabove the threshold, the WTRU may perform CBRA (e.g., and ifunsuccessful declares RLF). In an example, a WTRU may be configured witha second threshold higher than the beam suitability threshold (e.g.,allowing the WTRU to select the SUL carrier for a beam failure recoveryrequest before performing CBRA in RUL).

The WTRU may monitor the quality of the beams associated to SSB andCSI-RS in the cell. If RSRP of one or more beams are above thesuitability threshold (but not the second threshold (e.g., SUL)), thismay indicate to the gNB that the quality of the downlink transmission issufficiently good for the DL reception in the current bandwidth partsand frequencies configured to the WTRU, but not sufficient for apreamble transmission in RUL. The WTRU may consequently use SUL for theRA procedure.

Radio Link Failure may occur on the master cell group (MCG). The WTRUmay be configured with an UL/RUL on an MCG. The condition for triggeringRLF may depend on a configuration and/or activation state of an RUL/SUL.A WTRU that triggers RLF on an MCG (e.g. in LTE) may initiate are-establishment procedure. RLF may be triggered, for example, by one ormore of the following: (i) a maximum number of RLC retries reached foran MCG DRB, (ii) random access problems that may be indicated by an MCGMAC and/or (iii) T310 expiration, e.g., following detection of syncproblems that may be detected in L1.

A WTRU may have different behavior in response to one or moreRLF-related triggering conditions, for example, based on a configurationof an RUL/SUL. WTRU behavior may, for example, depend on a configurationand/or activation of an RUL/SUL (e.g. whether RUL and SUL are fullyconfigured in the WTRU, or only one is configured by RRC, and/or whethera WTRU may be currently indicated to use only a single UL). A WTRU may(e.g. in response to an associated condition that may correspond to RLF)trigger RLF and initiate re-establishment, or perform one or more (e.g.a combination of) alternate or additional actions. Alternate/additionalactions may include, for example, one or more of the following: (i)initiate a switch or request to use an SUL, or indicate to lower layersto initiate such a procedure (e.g. based on one or more examplesdiscussed with regard to an HO procedure); (ii) start a timer and waitfor an NW command to switch to another UL (e.g. SUL) and trigger RLFfollowed by re-establishment, for example, following expiration of atimer without receipt of a command from the NW; (iii) initiatetransmission of an RRC message on an SCG SRB (e.g. when a WTRU has anSCG SRB configured); (iv) initiate an action that generated a triggeringcondition (e.g. perform random access, or retry transmission in RLC) onanother UL (e.g. SUL), and possibly when another UL may currently beconfigured; (iv) start a timer, during which a WTRU may continue DLreception on a PCell, but may delay a UL transmission on a PCell untilit may receive an NW command (e.g. RRC, MAC CE, or L1) to switch a UL toa different carrier. A WTRU may declare RLF and initiatere-establishment, for example, following expiration of a timer withoutreceipt of a command from the NW; and/or (v) indicate (e.g. to lowerlayers) to reset counters associated with an RLF (e.g. number of RLCretries, number of PRACH transmission attempts).

The WTRU may trigger an RLF and initiate a re-establishment procedureunder one or more RLF-triggering conditions, for example, (e.g. only)when the WTRU may be configured with RUL and SUL and both are activated.A WTRU may initiate a RACH procedure or RACH-like procedure on an SUL,for example, when the WTRU may be configured with (e.g. only) RUL, ormay be configured with both RUL and SUL but indicated to use (e.g. only)RUL. A WTRU may use RACH-resources that are associated with an SULconfigured in dedicated or broadcast signaling to initiate a RACHprocedure on an SUL.

The WTRU may trigger RLF and initiate re-establishment, for example,when the WTRU is configured only with RUL, or configured with RUL andSUL but indicated to use (e.g. only) RUL. The WTRU may trigger RLF andinitiate re-establishment, for example, when conditions that meet RLFare associated (e.g. only) with DL problems (e.g. IS/OOS). The WTRU mayperform one or more (e.g. foregoing) actions, for example, when RLFtriggering conditions are associated with reaching a maximum number ofRLC retransmissions, or are associated with RACH problems that areindicated by a MAC entity.

The WTRU may implement a variety of different combinations, for example,in terms of triggering conditions for RLF depending on the configurationand/or activation state of RUL/SUL, outcomes, and actions.

The WTRU may trigger RLF based on a DL cell quality compared with athreshold. In an (e.g. additional or alternative example that may beused in combination with one or more other examples), the WTRU may havedifferent behavior in response to one or more RLF-triggering conditions,for example, based on cell quality at the time of or prior toRLF-triggering conditions. A decision at a WTRU may, for example, bebased on whether cell quality during the time period may be above orbelow a configured threshold. The WTRU may trigger RLF and initiatere-establishment, for example, when a measured quality of a serving cellDL may be above a threshold at or prior to a time that RLF-triggeringconditions may be met. The WTRU may perform one or more (e.g. foregoing)actions, for example, when cell quality may be below a threshold at thetime of RLF-triggering condition and/or at any time (e.g. a time instantor entire time period) prior to the RLF-triggering condition.

The time period may be configured by a network. The time periodconsidered in a WTRU decision may be specific to a type of RLFtriggering condition. The WTRU may, for example, maintain a (e.g.continuous) measure of cell quality of a DL cell. The WTRU may determinethe time period (e.g. for use in deciding whether to trigger RLF andperform re-establishment or to perform one or more actions), forexample, based on a specific trigger (e.g. time1 may be associated withmax RLC retransmissions, time2 may be associated with RACH problems,etc.). Examples of triggering RLF (e.g. based on one or more conditions)may be implemented by a WTRU and/or the NW in a variety of differentcombinations.

The WTRU may reset RLF-related counters/timers (e.g. at switch of UL).For example, the WTRU may reset counters and/or timers that may beassociated with RLF determination, for example, during an indication toswitch a UL. The WTRU may reset the counters during (e.g. only during) aswitch from a first UL type to a second UL type (e.g. RUL to SUL). TheWTRU may not reset the counters during a switch in the oppositedirection (e.g., SUL to RUL).

The WTRU may receive a command (e.g. from a network) to switch from anRUL to an SUL. The command may be received, for example, by an RRCmessage, a MAC CE or a DCI command in L1. The WTRU may (e.g. in responseto a command) reset a current value of an RLC retransmission counterthat is used for RLF determination. For example, the WTRU may reset thecounter that is associated with RACH problems (e.g. a RACH preambletransmission counter) or the like. The RRC layer of the WTRU may providean indication (e.g. to a MAC layer) to reset a counter, for example,upon reception of a message.

The WTRU may suspend RLF related counters/timers based on DL cellquality. The WTRU may avoid incrementing one or more timers/counters(e.g. associated with RLF determination), for example, when the WTRUdetermines a cell quality of a DL is below a threshold. A WTRU may avoidan increase of counters/timers, for example, for a UL operationperformed (e.g. only) on an RUL. The threshold may, for example, be thesame threshold that is configured for an SUL activation for initialaccess.

The WTRU may not increment an RLC retry counter, for example, when anRLC retransmission is performed while the WTRU is configured to use(e.g. only) an RUL, and/or when a retransmission has occurred during aperiod of time in which a measured DL cell quality has been below athreshold.

The RRC layer of a WTRU may indicate to lower layers (e.g. RLC, MAC, orPHY) at what time RLF related counters or timers may be suspended by thelower layers and when a counter/timer increase may be enabled. An RRClayer may make a determination, for example, based on measurements of DLcell quality of a serving cell.

The WTRU may implement one or more procedures to handle RLF on a SCGwhen configured with (e.g. or configurable with) a SUL. The WTRU may beconfigured with SUL/RUL on an MCG. Although described with reference toa SCG, the examples described may (e.g. also) be applicable to RLF on aMCG.

The WTRU may report in an SCG failure information message. For example,the WTRU may provide information in an SCG failure information messagethat may be sent to an MN, e.g., to inform the MN whether the SCGfailure occurred due to an RLF triggering condition on an RUL or an SUL.The MN may inform an SN of a need to configure or switch a UL of aPSCell for a WTRU to an SUL, for example. Information reported in an SCGfailure information message may include, for example, one or more of thefollowing: (i) a UL carrier (e.g. RUL or SUL, or ARFCN) on which an RLFtriggering condition has occurred (e.g. RLF due to max RLC retries whileon an RUL); (ii) configuration information of an RUL/SUL at the time ofor prior to an RLF (e.g. a WTRU may indicate a configuration conditionof an RUL/SUL such as being configured on a single UL, configured onboth ULs but indicated to use only one, or configured on both ULs andallowed to use both based on scheduling); and/or (iii) one or more (e.g.a set of) measurements of DL quality of a PSCell at the time of anRLF-triggering condition, or during a (e.g. configurable) time periodprior to an RLF-triggering condition.

The time period may be configured by a network. The time period may bedifferent for different RLF-triggering conditions. The time period maybe determined by a nature of an RLF-triggering condition itself. In anexample (e.g. for a max number of RLC retries on an SCG bearer), thetime period may start at a first RLC retransmission and may end when amaximum number of RLC retransmissions may be reached. The WTRU may, forexample, provide multiple measurements at predefined intervals during a(e.g. an entire) time period.

Partial failure of an SCG may occur based on configuration of anRUL/SUL. The WTRU may (e.g. in one or more cases) suspend SCGtransmissions, for example, depending on an RUL/SUL configuration on anSN and upon one or more conditions that may trigger an SCG failure. TheWTRU may (e.g. in other cases) perform one or more (e.g. a combinationof) actions such as, for example, one or more of the following: (i)initiate a switch or request to use an SUL on an SN, or provide anindication (e.g. to lower layers) to initiate such a procedure, e.g.,based on one or more HO procedures; (ii) start a timer and wait for anNW command to switch to another UL (e.g. SUL) on an SN (e.g. a WTRU maysuspend SCG transmissions, for example, following expiration of a timerwithout receipt of a command from an NW); (iii) initiate an action thatgenerated a triggering condition (e.g. perform random access or retrytransmission in RLC) on another UL (e.g. SUL) of the SN, and possibly ifthe other UL is currently configured (for example, if RLF due to RACHproblems occurs on the RUL, the WTRU may retry RACH on the SUL if (e.g.,and only if) the WTRU has been provided with an SUL configuration byRRC); (iv) start a timer during which a WTRU may continue DL receptionon a PSCell, but may delay UL transmission on the PSCell until itreceives an NW command (e.g. RRC, MAC CE, or L1) to switch the UL to adifferent carrier (e.g. a WTRU may suspend SCG transmissions, forexample, following expiration of a timer without receipt of a commandfrom the NW); and/or (v) provide an indication (e.g. to lower layers) toreset counters that may be associated with an SCG failure (e.g. numberof RLC retries, number of PRACH transmission attempts).

The condition for initiating an action may (e.g. further) depend on theUL that is configured during the time of an SCG failure. The WTRU mayinitiate an action based on one or more conditions, for example, (e.g.only) when the WTRU is configured with an RUL and not an SUL.

A WTRU may (e.g. when configured with a transmission using only an RUL)suspend SCG transmissions/reception for one or more SCG failure cases,such as: (i) integrity check failure; (ii) SRB3 reconfiguration failure,and/or (iii) RLF due to L1 problems. The WTRU may continue DL receptionon a PSCell but delay UL transmission on the PSCell until it receives areconfiguration or switch of the UL (e.g. to the SUL), for example, forone or more of the following: (i) RLF due to a maximum number of RLCretries by an SCG RLC, and/or (ii) RLF due to random access problems onan SCG MAC. The WTRU may (e.g. following a reconfiguration) re-attemptan UL transmission (e.g. PRACH or RLC retransmission) and may resetassociated timers/counters (e.g. number of RLC retries, PRACHtransmission counter).

Partial failure of an SCG may occur, for example, based on measurementson an RUL/SUL. In an example, which may be used in conjunction with oneor more other examples, a WTRU may (e.g. depending on measurements on aPSCell DL) initiate an action (e.g., instead of suspending an SCG). Forexample, the WTRU may initiate one or more actions upon reaching acondition of an SCG Failure, for example, for one or more of thefollowing: (i) SCG failure due to maximum RLC retries in an SCG; and/or(ii) SCG failure due to random access problems in an SCG MAC. Theconditions and actions may be combined in any combination to suspend SCGtransmission/reception.

A WTRU may transmit an SCG failure information message on an SUL. Forexample, the WTRU may transmit an SCG failure information message on anSUL of an SCG (e.g. instead of to an MN). The WTRU may perform atransmission on an SUL of an SCG, for example, (e.g. only) when one ormore (e.g. a combination of) conditions may be satisfied. Conditions mayinclude, for example, one or more of the following: (i) the WTRU isconfigured (e.g. only) with an RUL; (ii) the WTRU is configured with anRUL and an SUL, but is configured to transmit (e.g. only) on an RUL atthe time of an SCG failure; (iii) a DL quality of a PSCell is below athreshold or has been below a threshold (e.g. for a time instant orperiod) prior to an SCG failure; and/or (iv) an SCG has been triggeredby one or more (e.g. a set of) cases (e.g. SCG failure due to a maximumnumber of RLC retries and/or SCG failure due to random access problemsin an SCG).

In an (e.g. additional or alternative example that may be used inconjunction with one or more other examples), the WTRU may transmit theSCG failure information as a message in a RACH procedure (e.g. performedon an SUL). The WTRU may be configured (e.g. only) with RACH parametersfor an SUL (e.g. from broadcast signaling) and may transmit an SCGfailure information message, e.g., as part of an MSG3 of a RACHprocedure or RACH-like procedure that may be performed over an SUL.

The WTRU may select an UL (e.g., SUL or RUL) during a re-establishmentprocedure. For example, the WTRU may during a re-establishment procedureselect among multiple (e.g. two) configured ULs on which to initiate are-establishment procedure based on one or more criteria. The WTRU mayselect a UL (e.g. an SUL or RUL) on which to initiate a re-establishmentbased on one or more conditions, for example, when re-establishment isinitiated and a selected cell on which to perform re-establishmentprocedure may have an SUL configured. Conditions may include, forexample, one or more of the following: (i) the cell selected during are-establishment procedure; (ii) WTRU speed; (iii) WTRU battery power;(iv) DL channel quality of a cell; (v) a previous SUL/RUL configurationthat is provided to the WTRU by a cell (e.g. whether the WTRU wasconfigured with only one SUL or RUL, configured with both and activatedwith one or both), for example, when the WTRU was previously connectedto that cell; and/or (vi) the cause of the RLF that has caused the WTRUto perform reselection.

The WTRU may use the RUL, for example, when reselection has occurred toa cell that is different than the cell in which the WTRU triggered RLF,and may use an SUL, for example, when reselection occurred to the samecell in which RLF occurred. The WTRU may use RUL, for example, whenreselection has occurred to a cell that is different than the cell inwhich the WTRU triggered RLF, and when that cell may have DL qualityabove a threshold. Otherwise, the WTRU may use the SUL forre-establishment to the selected cell.

The WTRU may use a DL quality compared to a threshold to determinewhether RUL/SUL may be used for re-establishment, for example, when theselected cell is different from the cell in which the RLF was triggered.When the same cell is selected, the WTRU may use the SUL, for example,(e.g. only) when an RLF may have occurred while the WTRU was on the RUL.

In an (e.g. additional or alternative) example, a condition forselection of RUL/SUL when the same cell is selected may, for example,(e.g. further) depend on a cause of an RLF while the WTRU was connectedto the cell. For example, the WTRU may use the SUL when (e.g. only when)the WTRU is configured with RUL while connected to the cell, and/or theRLF occurred as a result of one or more of a subset of RLF triggeringconditions (e.g. MAX RLC retries expired or random access problems inthe MCG MAC entity).

The WTRU may prioritize cells with an SUL during reselectionre-establishment. For example, the WTRU may prioritize cells configuredwith an SUL during reselection, e.g., for a re-establishment procedure.Prioritization may be made between cells with equal quality.Prioritization may (e.g. also) be made for cells with quality that maydiffer by a (e.g. certain) maximum range. For example, the WTRU mayselect a cell with an SUL that is configured, for example, when twocells are measured with equal DL quality during cell reselection.Alternatively or additionally, the WTRU may (e.g. during cell selection)apply a quality offset (e.g. improved quality) for a cell that may havean SUL configured.

The network may provide the WTRU with System Information (SI). The WTRUmay perform SI request transmission for an RUL or SUL, for example, whenboth ULs are available based on system information. The WTRU's decisioncriteria for selection of an RUL or SUL may depend, for example, on oneor more of the following: (i) DL quality of a cell; (ii) WTRU speed;(iii) the WTRU battery power; (iv) type of SI requested; (v) broadcastinformation for an SI request procedure by a network; (vi) UL (e.g. SULor RUL) configured to the WTRU at the time of a request; (vii) a cell towhich the WTRU is making a request; and/or (viii) a type of SI requestprocedure (e.g. MSG1 or MSG3 based SI request procedure).

The WTRU may select the UL (RUL/SUL) based on DL quality of a cell. Forexample, the WTRU may select an SUL for transmission of an SI request,for example, when a DL quality of a cell is below a threshold. Thethreshold may or may not be the same as the threshold that is associatedwith selection of a UL for initial access. The WTRU may select a RUL,for example, when a DL quality of a cell is above a threshold.

The WTRU may perform UL selection based on WTRU speed. For example, theWTRU may select an SUL for transmission of an SI request, for example,when WTRU speed is higher than a threshold value. Otherwise, the WTRUmay select an RUL.

The WTRU may perform UL selection based on a type of SI requested. Forexample, the WTRU may select a SUL for transmission of an SI request forone or more SIBs or SI messages. The WTRU may, for example, utilize anSUL for an SI request for high priority SIB (e.g. requiring low latencyfor acquisition or associated with a high priority service).

The WTRU may perform UL selection based on broadcast information for anSI request procedure by a network. For example, the WTRU may select theSUL for transmission of an SI request based on an SI requestconfiguration (e.g. from an NW). The WTRU may receive (e.g. for anMSG1-based SI request procedure) in broadcast minimum SI, PRACHpreamble/resources that may be used to request specific SI messages orSIBs. The WTRU may receive an indication of which UL (e.g. SUL or RUL)resources are applicable to. The WTRU may perform an SI request in acorresponding UL. The WTRU may (e.g. additionally or alternatively)receive a configuration of PRACH preambles/resources for an RUL and anSUL. The WTRU may use another example procedure for selection of a ULfor an SI request.

UL selection based UL (e.g. SUL or RUL) may be configured to a WTRU,e.g., at the time of a request. In an example (e.g. for a WTRU inRRC_INACTIVE or RRC_CONNECTED), the WTRU may select a UL for an SIrequest, e.g., based on a configured or activated UL (e.g. SUL or RUL)for the WTRU. The WTRU may (e.g. in RRC_CONNECTED) may be configuredwith only an RUL transmission, or may be configured with SUL and RULwith only RUL active. The WTRU may follow configuration/activation (e.g.also) for an SI request while in RRC_INACTIVE. This may (e.g. also) beconditioned to a transmission of an SI request to the same cell whichlast configured the WTRU. The WTRU may use a configuration to determinea UL to use, for example, when an SI request may be made to the samecell that last configured/activated the SUL/RUL. The WTRU may use adifferent criteria, for example, when a request may be made to adifferent cell (e.g. due to mobility during RRC_INACTIVE).

Examples/conditions for the handling of SI may be combined in anycombination. For example, the WTRU may use an SUL for transmission of anSI request (e.g. only) for certain SIBs, for example, (e.g. only) when aDL quality of a cell may be below a threshold.

Access control may be implemented for SUL. For example, access controlconfiguration may be specific to a UL carrier. A WTRU may be configuredwith separate access control configuration for SUL independent of RULcarrier. The WTRU may apply the specific access control configurationassociated with the selected UL carrier. Such UL carrier specific accesscontrol may enforce independent overload control based on congestionstatus on the respective UL carrier.

The WTRU may be configured with an access control configuration for asubset of access categories on SUL (e.g., compared to RUL). The WTRU maybe configured (e.g., implicitly or explicitly) to prohibit transmissionsassociated with non-configured access categories on SUL. The WTRU may beconfigured (e.g., implicitly or explicitly) to reuse the access controlconfiguration from the RUL for the non-configured access categories onthe SUL. One or more access control configuration from SUL may overridethe baseline access control configuration from RUL.

The WTRU may base UL carrier selection on access control configuration(e.g., access control enforcing selective transmission on SUL). Forexample, a WTRU may be configured to select an uplink carrier fromplurality of uplink carriers based on one or more aspects related toaccess control. The WTRU may (e.g., for based on access controlconfiguration) determine the type of transmissions (e.g. accesscategories) which are allowed at a specific instant in time in a cell,and/or determine the UL carrier that may be used to perform suchtransmissions.

In an example, the WTRU may perform UL carrier selection based on accesscontrol configuration to route certain UL transmissions to the SUL(e.g., when transmissions over RUL is not desirable or not necessaryeven though the DL path loss is above a threshold). Examples ofsituations where routing UL transmissions to SUL may include situationsinvolving congestion in RUL, shorter transmissions, and/or transmissionsthat trigger a non-WTRU specific response.

In an example involving congestion in RUL, the WTRU may be configured toperform transmission on SUL when the transmissions on RUL are prohibitedbased on access barring factor configuration and/or when an accessbarring timer associated with RUL is running and/or transmissions on RULmay be temporarily delayed.

In an example involving shorter transmissions, certain transmissionsover SUL may lead to lesser overhead (e.g., the overhead of beamformingon RUL may not be required for short transmissions). The WTRU may beconfigured for transmissions over SUL for certain access categories(e.g., corresponding to RAN area update in INACTIVE state, etc.). In anexample, certain QoS flows that typically produce shorter data burstsmay be mapped to the SUL carrier.

In an example involving transmissions that trigger non-WTRU specificresponse, the WTRU may be configured to perform an on-demand SI request(e.g., dedicated preamble transmission) on the SUL carrier if the DL SItransmission is broadcasted.

The WTRU may be configured with separate access control parameters forSUL and RUL. A selective transmission may be enforced by allowingcertain access categories on SUL (and/or blocking those accesscategories on RUL). For example, the WTRU may be configured with asingle access control configuration, wherein the UL carrier to be usedfor certain access category may be configured as a part of accesscontrol parameter itself. For example, each access category may beassociated with either SUL or RUL. The WTRU may determine the accesscategory based on the characteristics of transmission (e.g., Qos flow IDor type of control message transmission). The WTRU may determine theapplicable UL carrier based on the access control configuration.

The WTRU may implement SUL BWP selection and switching procedures. Forexample, RRC may configure the WTRU with an association of each DL BWPand/or RUL BWP with one or multiple SUL BWP(s). This may allow the WTRUto maintain similar UL operation characteristics (e.g. BW, numerology,etc.), despite operating on different carriers.

In an example, an association procedure may be determined by the networkbased on one or more of: WTRU bandwidth operation (e.g., numerologysupported by the WTRU); WTRU RF capability (e.g., the ability to supporta specific BWP on SUL corresponding to a BWP on RUL); power savingpurposes; and/or WTRU service requirements (e.g., required bandwidth,latency, etc.).

A WTRU may receive the required association of SUL BWP and RUL BWPthrough RRC signaling. The WTRU may utilize such association to allow aswitch of BWP for both RUL and SUL using a single command from thenetwork. For example, the WTRU, upon receiving a BWP switch command forRUL/SUL, may perform (e.g., implicitly) a switch of the BWP for theother UL (SUL/RUL) to the BWP defined in the association.

A BWP association between RUL and SUL may be a one-to-one association ora one to many association. For example, in a one to one association, aBWP switch in RUL from BWP1 to BWP2 may automatically result in a BWPswitch in SUL to the BWP associated with BWP2. For example, in a one tomany association, a switch in RUL to a BWP having multiple associatedBWPs in SUL may result in additional rules at the WTRU to select the SULBWP, for example based on one or more of: DL RSRP/RSRQ; and/or similaraspects related to WTRU bandwidth operation, power savingsoptimizations, or numerology (e.g., as would be decided by the NW).

A BWP switching command in RUL may depend on the associated pairedBWP(s) in the SUL. This may allow the network to initiate a BWPswitching in RUL (e.g., only) if the paired BWP in SUL is adapted toWTRU capabilities and requirements.

In an example, when RUL and SUL are both configured to a WTRU, RRC mayconfigure an active BWP in RUL and an active BWP in SUL. Downlinkcontrol information (DCI) based activation/deactivation may besupported. The DCI may be in addition to the activation/deactivation viadedicated RRC signaling. The DCI may contain a one bit information tospecify which UL the activation/deactivation command is aimed for.

In an example, when (e.g., only) one UL is configured, (e.g., only) oneUL BWP per cell may active at a time. UL carrier switching may beallowed by the WTRU receiving a DCI activation/deactivation BWP commandto switch to the BWP of another UL carrier.

In an example, multiple BWPs may be active in the SUL, and the selectionor switching of BWPs in SUL may be initiated by the WTRU. The selectionor switching of BWPs in SUL may be based on DL measurement of theassociated cell.

In an example, if the WTRU is configured with both UL carriers (RUL andSUL) and the DL RSRP received by the WTRU is lower than a threshold, theWTRU may determine it needs to transmit in one of the configured SULBWPs.

In an example, a WTRU may select one of the SUL BWPs based on themeasured RSRQ: (i) for example, if the received RSRP is lower than athreshold, the WTRU may select the SUL associated to the low frequencyBWP; and (ii) if the received RSRP is higher than a threshold, but thereceived RSRQ is lower than another threshold, the WTRU may select thehigher frequency BWPs.

The WTRU may select the SUL associated to the low frequency BWP sinceRSRP provides information about signal strength. For example, a low RSRPmay be due to path loss attenuation or blockage and BWPs in lowerfrequency may be more robust to fading and blockage.

The WTRU may select the higher frequency BWPs since, the RSSI value(e.g., beside the RSRP value in the RSRQ calculation) containsinterference and noise information. For example, a low RSRQ with a highRSRP may be due to a predominance of interferences, and since higherfrequencies are more robust to interferences, the high frequency BWPsmay be more suitable to the WTRU.

Systems, methods, and instrumentalities have been disclosed forsupplementary uplink (SUL) in wireless systems. Cell suitabilitycriteria may be provided for cells configured with SUL. A WTRU mayreceive paging with an indication of a carrier (e.g. SUL or regularuplink (RUL)) in which to initiate part or all of an initial access. AWireless Transmit/Receive Unit (WTRU) that may be performingresponse-driven paging may provide (e.g. explicit) beam information forbeamforming of a paging message on a non-beamformed SUL. A handover (HO)procedure (e.g. carrier selection, configuration handling, HO failure)may be provided for a WTRU with a configured SUL. A WTRU may request achange of a configured UL. A WTRU may (e.g. autonomously) perform aswitch to a different (e.g. configured) uplink, e.g., when one or moreconditions may be met (e.g. conditional switch). Semi-persistentscheduling (SPS) resources/configuration may be relocated from a firstUL to a second UL. Duplication and UL path selection may be provided forradio resource control (RRC) messages in the presence of an SUL. A WTRUmay or may not trigger radio link failure (RLF), for example, based onwhether RLF related conditions occurred on SUL/RUL and based on SUL/RULconfiguration. Conditions may be set for suspension/reset of RLF relatedcounters/timers upon a switch between RUL/SUL. A WTRU may inform amaster node (MN) of an RUL/SUL configuration, for example, duringsecondary cell group (SCG) failure information reporting. A procedure(e.g. with corresponding WTRU behavior) may be implemented for partialSCG failure that may be triggered by SCG RLF on an RUL. A WTRU mayselect a UL carrier (e.g. SUL/RUL) on which to initiatere-establishment. Procedures may be provided for UL selection of asystem information (SI) request in the presence of an SUL/RUL.

The processes and instrumentalities described herein may apply in anycombination, may apply to other wireless technologies, and for otherservices.

A WTRU may refer to an identity of the physical device, or to the user'sidentity such as subscription related identities, e.g., MSISDN, SIP URI,etc. WTRU may refer to application-based identities, e.g., user namesthat may be used per application.

Each of the computing systems described herein may have one or morecomputer processors having memory that are configured with executableinstructions or hardware for accomplishing the functions describedherein including determining the parameters described herein and sendingand receiving messages between entities (e.g. WTRU and network) toaccomplish the described functions.

The processes described above may be implemented in a computer program,software, and/or firmware incorporated in a computer-readable medium forexecution by a computer and/or processor. Examples of computer-readablemedia include, but are not limited to, electronic signals (transmittedover wired and/or wireless connections) and/or computer-readable storagemedia. Examples of computer-readable storage media include, but are notlimited to, a read only memory (ROM), a random access memory (RAM), aregister, cache memory, semiconductor memory devices, magnetic mediasuch as, but not limited to, internal hard disks and removable disks,magneto-optical media, and/or optical media such as CD-ROM disks, and/ordigital versatile disks (DVDs). A processor in association with softwaremay be used to implement a radio frequency transceiver for use in aWTRU, terminal, base station, RNC, and/or any host computer.

What is claimed:
 1. A wireless transmit/receive unit (WTRU) comprising: a processor configured to: receive a first handover (HO) command to HO to a first cell associated with a first supplementary uplink (SUL) carrier and a first regular uplink (RUL) carrier, wherein the first HO command comprises an explicit indication of whether the first SUL carrier or the first RUL carrier to be used for random-access to complete the first HO; perform HO to the first cell in accordance with the first HO command; receive a second HO command to HO to a second cell associated with a second SUL carrier and a second RUL carrier; select an UL carrier for the second HO command based on whether a downlink reference signal received power (DL-RSRP) of the second SUL carrier is below a threshold, wherein, if the DL-RSRP of the second SUL carrier is below the threshold, then the second SUL carrier is selected as the UL carrier for the second HO, and if the DL-RSRP of the second SUL carrier is equal to or above the threshold, then the second RUL carrier is selected as the UL carrier for the second HO; and perform HO to the second cell in accordance with the second HO command.
 2. The WTRU of claim 1, wherein the first HO command is received via a dedicated RRC configuration.
 3. The WTRU of claim 1, wherein the threshold comprises an RSRP threshold that is specific to SUL carrier selection.
 4. The WTRU of claim 1, wherein the threshold applies to a plurality of bandwidth parts (BWPs) associated with the first cell.
 5. The WTRU of claim 1, wherein the processor is configured to receive the threshold when in an RRC_IDLE state when camped on the first cell.
 6. The WTRU of claim 1, wherein the first SUL carrier is in a frequency band that is lower than a frequency band of the first RUL carrier, and wherein the second SUL carrier is in a frequency band that is lower than a frequency band of the second RUL carrier.
 7. A method performed by a wireless transmit/receive unit (WTRU), the method comprising: receiving a first handover (HO) command; determining that the first HO command comprises an explicit indication of one uplink (UL) carrier for HO; selecting an UL carrier for the first HO command based on whether random-access channel (RACH) resources are provided for the first SUL carrier or the first RUL carrier in the first HO command; selecting an UL carrier for the first HO command based on whether random-access channel (RACH) resources are provided for a first supplementary uplink (SUL) or a first regular uplink (RUL) in the first HO command; performing HO to the selected UL carrier indicated by the first HO command; receiving a second HO command; determining that the second HO command comprises a configuration for both a second SUL and a second RUL in the second HO command; selecting an UL carrier for the second HO command based on whether a downlink reference signal received power (DL-RSRP) of the second SUL carrier is below a threshold, wherein, if the DL-RSRP of the second SUL carrier is below the threshold, then the second SUL carrier is selected as the UL carrier for the second HO, and if the DL-RSRP of the second SUL carrier is equal to or above the threshold, then the second RUL carrier is selected as the UL carrier for the second HO; and performing HO to the selected UL carrier indicated by the second HO command.
 8. The method of claim 7, wherein the first HO command is received via a dedicated RRC configuration.
 9. The method of claim 7, wherein the threshold comprises an RSRP threshold that is specific to SUL carrier selection.
 10. The method of claim 7, wherein the threshold applies to a plurality of bandwidth parts (BWPs) associated with the first cell.
 11. The method of claim 7, further comprising receiving the threshold when in an RRC_IDLE state when camped on the first cell.
 12. The method of claim 7, wherein the first SUL carrier is in a frequency band that is lower than a frequency band of the first RUL carrier, and wherein the second SUL carrier is in a frequency band that is lower than a frequency band of the second RUL carrier.
 13. A wireless transmit/receive unit (WTRU) comprising: a processor configured to: receive a handover (HO) command to HO to a cell associated with a supplementary uplink (SUL) carrier and an uplink (RUL) carrier; determine whether the HO command comprises an explicit indication of whether the SUL carrier or the RUL carrier to be used for random-access to complete the HO; wherein, upon a determination that the HO command comprises the explicit indication, the processor is further configured to perform HO to the cell in accordance with the explicit indication; and wherein, upon a determination that the HO command does not comprise the explicit indication, the processor is further configured to: measure a reference signal received power (RSRP) associated with the cell; compare the RSRP associated with the cell to a threshold; and perform HO to the cell based on the comparison of the RSRP associated with the cell to the threshold.
 14. The WTRU of claim 13, wherein the processor is configured to select the SUL carrier as the UL carrier for HO when the RSRP is below the threshold, and configured to select the RUL carrier as the UL carrier for HO when the RSRP is above the threshold.
 15. The WTRU of claim 13, wherein the HO command is received via a dedicated RRC configuration.
 16. The WTRU of claim 13, wherein the threshold comprises an RSRP threshold that is specific to SUL carrier selection.
 17. The WTRU of claim 13, wherein the threshold applies to a plurality of bandwidth parts (BWPs) associated with the cell.
 18. The WTRU of claim 13, wherein the processor is configured to receive the threshold when in an RRC_IDLE state when camped on the first cell.
 19. The WTRU of claim 13, wherein the SUL carrier is in a frequency band that is lower than a frequency band of the RUL carrier. 